New Experiment: Abilities toggle

What problem does this address?

As we're already adding new abilities (e.g. #691, #774) and considering abilities outside of just read capabilities (e.g. #764), I would like to see us wrap these at least within a single "Ability APIs" sort of Admin Experiment. Read-only abilities are one thing to have automatically exposed on sites, but ones that could be destructive feel like it should be purposely enabled by a site owner before those are available.

What is your proposed solution?

For now, let's at least wrap available Ability APIs from the AI plugin in an experiment so that they're purposely enabled for usage/testing.

Why is this important to you?

There's a potential future state where we have so many abilities across CRUD operations that it would be not as easy to just "enable all abilities" sort of a settings toggle and perhaps then consider updating the Abilities Explorer to be a broader experiment where within that you can enable individual abilities or types of abilities or whatever.

I have searched existing issues and this is not a duplicate.

• Yes