WIP: Backport from Mastodon FE main to support the "Direct messages" column and Lists
The code in this MR is quite different from the current mastofe code:
- I merged the Mastodon FE changes from the main repo into the Pleroma mastofe fork (mostly manually!). As far as I can tell it works and adds support for the "Direct messages" column and also for Lists.
- I removed Mute, Pin and Embed because they are as far as I can see not supported (or in the case of Mute, there is server support but it does not work)
- I also removed "Hidden domains" as I have no idea if that works
- I left the "Report" feature. I'm not sure if it works though.
- I did not change over to the new style sheets because I actually like the current styling better.
I've tagged this as "WIP" because it would be best if someone else tried it out as well.
