chore: Add support for typed nested lists in autogen

[manupedrozo]

Description

Adding a custom NestedList terraform type for autogen usage following the work done at #3801 which added a custom Object type.

Note that NestedList supports nested objects but not Terraform attr types, e.g. types.string. These will be covered in the next PR.

I was initially planning to support both in the same custom type but it requires a lot of extra branching so instead we'll introduce a different type for attr types.
This is just like schema.ListNestedAttribute is used for nested objects and schema.ListAttribute for primitives.

Custom TF types docs: https://developer.hashicorp.com/terraform/plugin/framework/handling-data/types/custom

Link to any related issue(s): CLOUDP-353169

Type of change:

• Bug fix (non-breaking change which fixes an issue). Please, add the "bug" label to the PR.
• New feature (non-breaking change which adds functionality). Please, add the "enhancement" label to the PR. A migration guide must be created or updated if the new feature will go in a major version.
• Breaking change (fix or feature that would cause existing functionality to not work as expected). Please, add the "breaking change" label to the PR. A migration guide must be created or updated.
• This change requires a documentation update
• Documentation fix/enhancement

Required Checklist:

• I have signed the MongoDB CLA
• I have read the contributing guides
• I have checked that this change does not generate any credentials and that they are NOT accidentally logged anywhere.
• I have added tests that prove my fix is effective or that my feature works per HashiCorp requirements
• I have added any necessary documentation (if appropriate)
• I have run make fmt and formatted my code
• If changes include deprecations or removals I have added appropriate changelog entries.
• If changes include removal or addition of 3rd party GitHub actions, I updated our internal document. Reach out to the APIx Integration slack channel to get access to the internal document.

Further comments

[manupedrozo]

I'll rename this package in a separate PR to customtypes to follow convention.