Feature request: add support for project feature flags #3350

Description of the problem, including code/CLI snippet

Does this library have support for project feature flags? The API doc is below:

https://docs.gitlab.com/api/feature_flags/

It seems this is currently not available but please confirm. If it's not available, would be great to add support for it.

Also, the following docs page currently named as "Feature Flags". This is a bit confusing/misleading because it's not the same as the above mentioned API endpoint. It's for managing features of GitLab instance itself.

https://python-gitlab.readthedocs.io/en/stable/gl_objects/features.html

Would be great to clarify the docs for the above page for avoiding confusions.

Expected Behavior

Ability to set project feature flags

Actual Behavior

Cannot find options for managing project feature flags.

Specifications

• python-gitlab version: 8.x
• Gitlab server version (or gitlab.com): 18.8