Upgrade to Godot 3.3

[athariqk]

Reset buttons focus mode in various places due to it being marked deprecated with 3.3

Engine related issues this definitely fixes:
Closes #1126 (no problems found on testing)
Closes #1095

Others may need some reviewings to see if they are properly fixed with the new version.

Closes #2204
closes #2058

[hhyyrylainen]

I'll do the CI image upgrading part (I was kinda waiting until I got the new DevCenter CI working before working on the godot upgrade myself) and CircleCI config once this is otherwise ready.

[athariqk]

No problem, I'll mark this as a draft for now.

[hhyyrylainen]

@Kasterisk could you fix the conflicts with master and update this (MicrobeEditor.tscn)? I'll have the CI images to ready to go by then.

[athariqk]

Sure, will do that in a moment.

[hhyyrylainen]

Looks like there's even a maintenance release now: https://godotengine.org/article/maintenance-release-godot-3-3-2
After the conflicts are resolved, I'll update to that maintenance version (though, I'll leave CircleCI running on 3.3 as it shouldn't really affect things to just use it for the jetbrains check).

[athariqk]

Solved merge conflict.

[hhyyrylainen]

I saw something going on with the jetbrains tools here, so as I need to make a new image anyway, I'll update them as well... so it's going to take until tomorrow.

[hhyyrylainen]

I did the changes this needs. Didn't test yet if this closes all the mentioned issues. The CI failure seems to be that for some reason the CDN doesn't want to let anyone download the new CI image I just uploaded, but it seems to get farther and farther when I manually download, so maybe a little bit of time will sort that out.