feat: implement code generated handler framework

packages/@aws-cdk/custom-resource-handlers/lib/custom-resources-framework/README.md

@@ -0,0 +1,87 @@
+# AWS CDK Custom Resource Framework
+
+The CDK custom resource framework is an internal framework developed to establish best practices, runtime enforcement, and consistency for custom resource providers and their associated source code. 
+
+## Custom Resource Framework Concepts
+
+Custom resource providers can be created in one of three forms - `CdkFunction`, `CdkSingletonFunction`, or `CdkCustomResourceProvider`. These three custom resource provider formats are a code generated wrapper around the lambda `Function`, lambda `SingletonFunction`, and `CustomResourceProvider` constructs, respectively. These new CDK prefixed constructs will offer the same behavior and initialization options as their parent minus the ability to configure the following properties during construction:
+- `handler` - the name of the method within your code that the provider calls to execute your function
+- `code` - the source code of your provider
+- `codeDirectory` - a local file system directory with the provider's code
+- `runtime` - the runtime environment for the provider that you are uploading
+
+Instead, these properties will be automatically generated using the `ProviderProps` configured in the [config](./config.ts) file:
+- `type`: the custom resource provider type to generate
+- `sourceCode`: the source code that will be executed by the provider
+- `compatibleRuntimes`: runtimes that are compatible with the provider's source code
+- `handler`: the name of the method within your code that the provider calls to execute your function
+
+The [config](./config.ts) file is structured with the top most level mapping to a `aws-cdk-lib` module, i.e., `aws-s3`, `aws-dynamodb`, etc. Each service can contain one or more provider modules. Provider modules are containers for custom resource providers and will be rendered as a code generated file. Each provider module can contain one or more `ProviderProps` objects. Each `ProviderProps` object contains all the necessary information required to generate a single custom resource provider. The following example shows a more structural breakdown of how the [config](./config.ts) file is configured:
+
+```ts
+const config = {
+  'aws-s3': { // the aws-cdk-lib module
+    'replica-provider': [ // the custom resource provider module
+      // custom resource provider defined as ProviderProps object
+      {
+        // the custom resource provider type - `CdkFunction`
+        type: ComponentType.CDK_FUNCTION,
+        // the source code that the provider will execute
+        sourceCode: path.resolve(__dirname, '..', 'aws-dynamodb', 'replica-handler', 'index.ts'),
+        // runtimes that are compatible with the source code
+        compatibleRuntimes: [Runtime.NODEJS_18_X],
+        // the handler in the source code that the provider will execute
+        handler: 'index.onEventHandler',
+      },
+    ],
+  },
+  'aws-stepfunctions-tasks': {
+    // contains multiple custom resource provider modules
+    'eval-nodejs-provider': [
+      {
+        // the custom resource provider type - `CdkSingletonFunction`
+        type: ProviderType.CDK_SINGLETON_FUNCTION,
+        sourceCode: path.resolve(__dirname, '..', 'aws-stepfunctions-tasks', 'eval-nodejs-handler', 'index.ts'),
+        compatibleRuntimes: [Runtime.NODEJS_18_X],
+      },
+    ],
+    'role-policy-provider': [
+      {
+        type: ProviderType.CDK_SINGLETON_FUNCTION,
+        sourceCode: path.resolve(__dirname, '..', 'aws-stepfunctions-tasks', 'role-policy-handler', 'index.py'),
+        compatibleRuntimes: [Runtime.PYTHON_3_9],
+        // prevent minify and bundle flag is set since the source code is a python file
+        preventMinifyAndBundle: true,
+      },
+    ],
+  },
+};
+```
+
+Code generation for the provider modules is triggered when this package - `@aws-cdk/custom-resource-handlers` - is built. Importantly, this framework is also responsible for minifying and bundling the custom resource providers' source code and dependencies. A flag named `preventMinifyAndBundle` can be configured as part of the `ProviderProps` to prevent minifying and bundling the source code for a specific provider. This flag is `false` by default and is only needed for Python files or for JavaScript/TypeScript files containing require imports.
+
+Once built, all generated code and bundled source code will be written to `@aws-cdk/custom-resource-handlers/dist`. The top level field in the [config](./config.ts) file defining individual `aws-cdk-lib` modules will be used to create specific directories within `@aws-cdk/custom-resource-handlers/dist` and each provider module will be a separate code generated file within these directories named as `<provider-module>.generated.ts`. As an example, the sample [config](./config.ts) file above would create the following file structure:
+
+|--- @aws-cdk
+|   |--- custom-resource-handlers
+|   |   |--- dist
+|   |   |   |--- aws-s3
+|   |   |   |   |--- replica-handler
+|   |   |   |   |   |--- index.js
+|   |   |   |   |--- replica-provider.generated.ts
+|   |   |   |--- aws-stepfunctions-tasks
+|   |   |   |   |--- eval-nodejs-handler
+|   |   |   |   |   |--- index.js
+|   |   |   |   |--- role-policy-handler
+|   |   |   |   |   |--- index.py
+|   |   |   |   |--- eval-nodejs-provider.generated.ts
+|   |   |   |   |--- role-policy-provider.generated.ts
+
+The code generated custom resource providers are usable in `aws-cdk-lib` once `aws-cdk-lib` is built. The custom resource providers will be consumable from `aws-cdk-lib/custom-resource-handlers/dist` and the file structure therein will match what was generated in `@aws-cdk/custom-resource-handlers/dist` except for providers defined in `core`. To prevent circular dependencies, all custom resource providers defined in `core`and any associated source code will be consumable from `aws-cdk-lib/core/dist/core`.
+
+## Creating a Custom Resource Provider
+
+Creating a new custom resource provider involves three steps:
+1. Add the custom resource provider's source code to `@aws-cdk/custom-resource-handlers/lib/<aws-cdk-lib-module>`
+2. Update the [config](./config.ts) file with the custom resource provider to generate by specifying all required `ProviderProps`.
+3. At this point you can directly build `@aws-cdk/custom-resource-handlers` with `yarn build` to view the generated provider in `@aws-cdk/custom-resource-handlers/dist`. Alternatively, you can build `aws-cdk-lib` with `npx lerna run build --scope=aws-cdk-lib --skip-nx-cache` to make the generated provider available for use within `aws-cdk-lib`