Expose project access control in the API

[nijel]

Describe the problem

Some project fields are not exposed in the API, at least:

• Access control
• Translation memory contribution

Solution brainstorm

These should be added sharing logic with the ProjectSettingsForm.clean which handles specifics of some setups like Hosted Weblate.

Describe alternatives you have considered

No response

Screenshots

No response

Additional context

https://github.com/orgs/WeblateOrg/discussions/15292