Implement GetInviteDetails

[rdimitrov]

Summary

The following PR implements the GetInviteDetails API for getting additional metadata info for invite codes. This is intended to be a public API accessed by unauthenticated users.

Fixes #(related issue)

Change Type

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• Bug fix (resolves an issue without affecting existing features)
• Feature (adds new functionality without breaking changes)
• Breaking change (may impact existing functionalities or require documentation updates)
• Documentation (updates or additions to documentation)
• Refactoring or test improvements (no bug fixes or new functionality)

Testing

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Review Checklist:

• Reviewed my own code for quality and clarity.
• Added comments to complex or tricky code sections.
• Updated any affected documentation.
• Included tests that validate the fix or feature.
• Checked that related changes are merged.

[dmjb]

This could probably benefit from unit test coverage as well, although not as much as the other PR.

[coveralls]

coverage: 53.394% (-0.08%) from 53.476%
when pulling dffd69c on invite-service
into 07f93e0 on main.

[rdimitrov]

This could probably benefit from unit test coverage as well, although not as much as the other PR.

Created #3670