Bug/36827 creating work package in status not available for work package type

[ulferts]

[#36827] Creating work package in status not available for work package type

Currently whether the status of a to be created work package is included in the workflows is not checked at all. So every status provided by the client is accepted.

This PR changes the behaviour so that for an unpersisted work package, only status that are included in the workflow as either the old status (the status from which can be transitioned) or the new status (the status to which can be transitioned) are valid.

TODO

• [ ] An invalid status will still be displayed (without an error message) as selected in the split view if assigned by the filter value (see linked bug report). Only after the user clicks on "Save" is the error displayed. As we don't validate initially, the frontend should only apply valid filter values.

https://community.openproject.org/work_packages/36827