17402 complete status endpoint

[``* `#17402` Complete status endpoint``](https://community.openproject.org/work_packages/17402)
Why did you drop that?
It did exist in APIv2 and it is actually part of the model, isn't it?

The vision (as far as I am concerned), is that *some day(tm)* all aspects of OpenProject are available over the API... so I do not see the reason to spare out arbitrary parts...