feat(stepfunctions): distributed map construct (#28821)

Adds support for Step Functions Map state in Distributed mode. Currently, in order to create a Distributed Map in CDK, CDK users have to define a Custom State containing their Amazon States Language definition. 

This solution consists of the creation of a new L2 construct, `DistributedMap`. This design decision was made due to the fact that some fields are exclusive to Distributed Maps, such as `ItemReader`. Adding support for it through the existing `Map` L2 construct would lead to some fields being conditionally available.

Some design decisions that were made:
- I created an abstract class `MapBase` that encapsulates all fields currently supported by both `inline` and `distributed` maps. This includes all currently supported fields in the CDK except for `iterator` and `parameters` (deprecated fields). Those are now part of the Map subclass which extends `MapBase`. All new Distributed Maps fields are part of the new `DistributedMap` construct (also a subclass of `MapBase`)
- Permissions specific to Distributed Maps are added as part of this new construct

Thanks to @beck3905 and their PR #24331 for inspiration. A lot of the ideas here are re-used from the PR cited.

Closes #23216 

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