Enable comment editing across all platform sections

Summary

Editing comments is currently impossible on the platform. The feature should be added consistently across posts, projects, news, and gists, preferably with inline editing.

Steps to Reproduce

1. Navigate to any section of the platform (posts, projects, news, or gists).
2. Attempt to edit an existing comment.
3. Observe that no edit option is available.

Expected Behaviour

Users should be able to edit their comments inline across all sections of the platform.

Actual Behaviour

Editing comments is not possible anywhere on the platform.

Environment

Not provided.

Reported by retoor via DevPlace.