SolutionContainer refactors (#2954)

* removes unused method

* Code uncluttering (Also removed the netcode, color code, and visuals, need to rewrite)

* SolutionContainerVisualState

* Removes caching of SolutionContainer Color

* ChemicalsAdded() and ChemicalsRemoved() for updating appearance and handling reaction checks

* SolutionContainerComponentState

* Netcode

* ChemMasterComponent no longer creates a SolutionContainerComponent with new(), uses a Solution instead

* Enable nullable in SolutionContainer implementations

* Some review fixes

* uses IReadOnlyLists in ChemMaster

* Comments

* review fixes 3

* ReagentUnit documentation

* Review fixes

* spelling fix

* spelling 2

* typo

Co-authored-by: py01 <pyronetics01@gmail.com>

Content.Server/GameObjects/Components/Interactable/WelderComponent.cs

@@ -1,4 +1,4 @@
-#nullable enable
+#nullable enable
 using System;
 using System.Threading.Tasks;
 using Content.Server.Atmos;