Various Improvements to NanoChat (#2922)

* Port improvements to NanoChat from Einstein-Engines and Goob-Station

* fix duplicate translation key

* add missing space

* Properly mark DeltaV changes

* Allow muting individual NanoChat users, NanoChat UI to put per-chat buttons next to the message box

* remove leftover from testing stuff

* cycle through inputs with tab, confirm with enter; for new and edit chat

* Add channel switching with (Shift+)Alt+Up/Down; Discord-Style

* better null check

* another better null check

* Implement changes from ImpStation PR

* Rename ContactControl -> ContactContainer

* Requested changes

* Move Loc to _DV, don't register system as manager

* I'm so smart :)

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Co-authored-by: Alex C <alex91905@yahoo.com>

Resources/Textures/_DV/Interface/VerbIcons/ATTRIBUTION.txt

@@ -3,3 +3,6 @@ Licensed under CC BY 4.0
 
 hamburger_icon.svg.png
 Released into the public domain
+
+edit.svg.png by H2D2 Design under MIT License
+https://www.svgrepo.com/svg/453928/edit