Feature/backend/list of collaborators

[vansh909]

Closes: #1193
Parent issue: #1179

Describe the add-ons or changes you've made

• Implemented a new API endpoint to fetch the list of collaborators for a project.
• The API ensures only authorized users (project owner) can access this information.
• The response returns the list of collaborators.
• Added proper error handling for scenarios like missing or invalid project IDs.

###Screenshot

Type of change

What sort of change have you made:

• New feature

Note to reviewers

• Feature developed as part of the Invite Multiple Collaborators to a Project task.

[vercel]

@vansh909 is attempting to deploy a commit to the avdheshvarshney's projects Team on Vercel.

A member of the Team first needs to authorize it.

[github-actions]

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