Add bottom dock tab style setting

[KoBeWi]

Fixes #113054

This PR adds a new interface/editor/bottom_dock_tab_style editor setting, which can be used to set the tab style for bottom docks separately (I assume most users wouldn't want them icon-only, even if they use that option for vertical docks, idk).

Also adds a new EditorDock property - force_show_icon. EditorLog (aka Output) uses it to display error icon even if tabs are text-only.

And finally, Output is now EditorDock (part of #113024). I assigned it a new icon, which is error icon but white

It only shows when bottom dock icons are enabled (other docks don't have icons yet).

[Mickeon]

The new editor setting feels like a bit of a hack, I can't quite put why.
Maybe it's because interface/editor/dock_tab_style is now oddly ambiguous in both name and description. I would suggest at least changing its original description, too. Preferably the setting should be renamed, but perhaps that's overkill because all of this logic is emerging just to retain the same features as before during this refactoring.

[Mickeon]

Docs ok. But the docks should be okay, too.

[lodetrick]

To be honest I don't think we need the editor setting just yet; the bottom dock with only icons does look weird right now but once all of the bottom docks are converted it will look a lot better. I think the feeling is just because of how uneven it is. The editor setting also feels like future-proofing, I think it should be included it if reports are coming in about the icons on the bottom panel but I think its just too early to tell.

[KoBeWi]

We have 17 bottom docks. Only 5 of them are always visible, the others will appear and disappear and change positions, it's very different from the side docks. Also you have lots of space at the bottom, so icon-only mode does not really help with anything. I doubt people will use it much, even if they use it for the side docks.

[Repiteo]

Thanks!

[lodetrick]

I pulled from master and the icons don't update properly, the setting only goes into effect if I close the editor and reopen it, or force an update by moving dock to another slot.

Edit: Both settings now don't update properly

[KoBeWi]

Yeah, I noticed it and just made a fix. Will push soon.

[Maran23]

One note from my side: With #113051 as a potential improvement, the interface/editor/bottom_dock_tab_style might not be the best name then. As you may could even put those docks at the top. Then something like interface/editor/horizontal_dock_tab_style would fit better. Just something for consideration in the future.

[KoBeWi]

Main screen docks will get another setting (it will be the last one).
Although we might get another horizontal dock slot, so maybe the name is not ideal. For now it works though.