HEIC Support

[fastrack20]

It seems that when you try and post an HEIC photo, it will not upload. Pictures need to be converted to jpg before posting.

Tested on Tuaky 23.0

Saw this discussion but figured I'd post as an issue.

Discussed in #2770

^{Originally posted by sbeee November 7, 2022}
Hi, because of missing HEIC support everytime when I post a picture I've to convert it to JPG first. This is impractical.

Btw...the "original" mastodon Android App supports HEIC.