File upload size limit function

[KormiMeiko]

Summary

You can set a threshold for the upload size of files. If the threshold is exceeded, upload is not allowed.

You can also specify the upload size for specific file types (such as pictures, audio and video files).

[okpierre]

This would be a good feature for all instance admin to set for their community.

Maybe something like:
media upload limit: 5MB

Then display message to user when file size is over limit when composing note and adding media

For now, if you use nginx you can set client_max_body_size but it's not user friendly way