Added Shopify Themes CLI Plugin (The Second Attempt™️)

[jerryzhou196]

Overview

This PR fully implements the Shopify Theme CLI Shell Plugin. It builds off of the great work done by @ammiranda and @hculea on #397.

Shopify.CLI.Integration.Demo.mov

The video shows the 1Password Shopify Shell Plugin integrating with the shopify theme CLI and a theme access API key.

Incidentally, there were a few interesting things I stumbled upon.

1. I couldn't implement the importer because the Shopify CLI stores the environment file by project directory rather than a fixed path.
   (instead of something like ~/config.toml, it's {PROJECT_DIRECTORY}/shopify.theme.toml).

2. I noticed that importer.NoOp() would cause the op plugin init flow to fail with [ERROR]... credential not found for the Import into 1Password... option. The same issue was mentioned in new(mongosh): Support mongosh executable for connecting to a MongoDB database #283. Without being able to see the underlying code causing the error, I provide a band-aid solution in this PR that fixes the importer.NoOp() implementation to no longer give this error.

3. Shopify CLI also has a lone Webhooks CLI integration called shopify webhook trigger that requires a --client-secret passkey. I'm very happy to implement this too. What are your thoughts?

Type of change

• Created a new plugin
• Improved an existing plugin
• Fixed a bug in an existing plugin
• Improved contributor utilities or experience

Related Issue(s)

• Resolves: New plugin: Shopify #201
• Relates: Add Shopify CLI plugin #397
• Relates: new(mongosh): Support mongosh executable for connecting to a MongoDB database #283

How To Test

1. Download the Shopify CLI.
2. Create a Shopify Store on Shopify and configure the theme access app to your store.
3. Provision a key through the theme access portal.
   (Side note: Not sure how to test the automatic chrome extension detection import here)
   
4. Build the plugin and run op plugin init shopify. Store the key through the import option.
5. Try running the protected theme commands without the --password option or the Shopify built-in authentication. It should work.

Changelog

Added Shopify Themes Plugin.
Added an empty attempt to importer.NoOp() to correctly function without error.

[AndyTitu]

Thanks for the contribution and thanks for providing the usage video, that's very helpful when reviewing this PR! Looks good to me apart from a couple of minor doc suggestions. Will forward this for a security review.

Also, there are a few tests failing.