adding ResourceShares support

[ehmanel]

Description

This PR adds support for ResourceShares, requested in #1108

TODOs

Read the Gruntwork contribution guidelines.

• Update the docs.
• Run the relevant tests successfully, including pre-commit checks.
• Ensure any 3rd party code adheres with our license policy or delete this line if its not applicable.
• Include release notes. If this PR is backward incompatible, include a migration guide.
• Attention Grunts - if this PR adds support for a new resource, ensure the nuke_sandbox and nuke_phxdevops jobs in .circleci/config.yml have been updated with appropriate exclusions (either directly in the job or via the .circleci/nuke_config.yml file) to prevent nuking IAM roles, groups, resources, etc that are important for the test accounts.

Release Notes

added support for ResourceShares

^{Elias Ehmann elias.ehmann@mercedes-benz.com, Mercedes-Benz AG on behalf of Mercedes-Benz Tech Innovation GmbH, Provider Information}

[james00012]

Hi @ehmanel, is this PR ready for review. I see [WIP] in title. Please ping me once it's ready for review.

[ehmanel]

@james00012

[james00012]

Hi @ehmanel, friendly ping.

[james00012]

Hi @ehmanel, can you also handle the branch conflicts? Thanks

[james00012]

Thanks for addressing the prior feedback! The go.mod fix and status filter look good. However, the test data needs to be updated to include Status:types.ResourceShareStatusActive on shares that should pass the filter — currently all tests will fail because every share gets skipped by the new status check. Could you also add a test share with a non-active status (e.g., DELETED) to verify the filter works in both directions?