Mid-measure Fine, Da Capo, etc...

Describe the bug
MuseScore currently supports repeat signs such as Fine, Da Capo and Dal Segno only if referred to the end of a measure, and the playback reflects this. Sure, you can work around this by inserting the text in question to the end of a measure, "stretching" its and the following measure's meter and make the barline between the two invisible, but this often causes file corruption and incorrect numbering of the measures.

Feature suggestion
While I'm not sure if this would clash with the current code, I think implementing a way to let users add these indications to any beat of a measure would be a nice addition to the app; in my experience a lot of pre-1800s music, let's say galant opera arias, often present this feature in the original manuscript and in their 20th century editions, see e.g. this Handel aria:

and its Chrysander edition (the Fine refers to the fermata marking and separates part A of the aria, which is going to be repeated after part B, and part B, which as you can see "starts" mid-measure, this means that the repeat of part A will end on that low A and won't include those C and B in the basso continuo):

I also see a possible use in more recent music for composers who are maybe interested in minimalism and "looping" fragments of music or more precise control over repeats overall.

I know this is more of a feature request than a bug, I'm sorry but I'm not too practical with properly reporting issues.
Thanks in advance!

No source files, tests, or entry points are identified in the issue. Start by locating the implementation and playback handling for Fine, Da Capo, and Dal Segno; done should allow these indications at any beat while preserving correct playback, measure numbering, and file integrity.