Branches cleanup proposal (and one decent request)

[stronk7]

There are a bunch of very-old branches in this repository:

1. Link: https://github.com/moodlehq/moodle-local_chatlogs/branches/all
2. Is it ok if we proceed to remove some of them:
   • telegram-import: Original code to import from telegram rooms, now in "main" since 8y ago.
   • fix-get_system_context: Already merged too (11y ago).
   • skodak-cleanup: Already merged too (12y ago).
3. There is the "mobile" branch that doesn't seem to be merged, not sure about that one.
4. The rest are very old "MOODLE_XY_STABLE" branches that I don't mind much keeping them.

Ciao :-)

[stronk7]

Also, one request...

5. would be ok if I add a new branch here, to the upstream repository, named first_matrix_version with the changes needed to support matrix rooms, so I can test it in our integration team moodle site? It would help to have a deployed version where we can see it in action.

(I've it working locally, but being able to install it @ our integration site will allow the team to play with it a suggest/discuss stuff).