1044 readonly
This switches most study forms into readonly-mode if the study is finished. There are some exceptions/follow-up tasks:
- filters are handled differently (because they don't use a regular form and also because they are disabled in recruitment, too) [see !727 (merged)]
- members are handled differently (because that is not a single form but several sub-views) [to be done]
- sessions (as part of the study form) are not yet readonly [to be done]