Fix LC invite and IG filtering issues

[DevWithPranav]

No description provided.

[greptile-apps]

Greptile Summary

This PR fixes learning-circle invitation handling and filters interest groups by status. The main changes are:

• Accept link_id from either the request URL or body.
• Add tests for invitation acceptance, rejection, and invalid identifiers.
• Limit interest-group list and detail responses to active groups.
• Add the creator MUID to project responses.

Confidence Score: 5/5

This looks safe to merge.

• No blocking issues found in the changed code.

Important Files Changed

Filename	Overview
api/common/common_views.py	Filters public interest-group list and detail queries to active groups.
api/dashboard/ig/dash_ig_view.py	Filters the dashboard interest-group list to active groups.
api/dashboard/learningcircle/learningcircle_views.py	Supports invitation identifiers from both URL parameters and request bodies.
api/dashboard/learningcircle/tests/test_learningcircle.py	Tests both invitation request forms and their main error cases.
api/dashboard/projects/projects_serializer.py	Adds the project creator's MUID to serialized responses.
utils/types.py	Defines shared interest-group status values.

_{Reviews (1): Last reviewed commit: "Merge pull request #3055 from gtech-mule..." | Re-trigger Greptile}