Toolshed (#17895)

* ogh

* i should save my work

* ogh

* hhcdfhjbghshbxdfhghshc
- lots of bugs in parsing still
- invocation is a stub

* expr parsing works

* awawa

* Saving work

* Improve APIs a bit all around, add shortcuts.

* awa

* awa

* AAAAAA

* save work

* Move shit to engine

* lord

* bql is kill

* forgot the fucking bike rack

* bql is kill for real

* pjb will kill me

* aughfhbdj

* adgddf

* gdsgvfvxshngfgh

* b

* hfsjhghj

* a

* tf you mean i have to document it

* follow C# standards

* Assorted cleanup and documentation pass, minor bugfix in ValueRefParser.

* Start porting old commands, remove that pesky prefix in favor of integrating with the shell.

* bw

* Fix valueref up a bit, improve autocomplete for it.

* awa

* fix tests

* git shut up

* Arithmetic commands.

* parse improvements

* Update engine.

---------

Co-authored-by: moonheart08 <moonheart08@users.noreply.github.com>

Content.IntegrationTests/Tests/Commands/RejuvenateTest.cs

@@ -1,4 +1,5 @@
 using Content.Server.Administration.Commands;
+using Content.Server.Administration.Systems;
 using Content.Shared.Damage;
 using Content.Shared.Damage.Prototypes;
 using Content.Shared.FixedPoint;
@@ -11,7 +12,7 @@ using Robust.Shared.Prototypes;
 namespace Content.IntegrationTests.Tests.Commands
 {
     [TestFixture]
-    [TestOf(typeof(RejuvenateCommand))]
+    [TestOf(typeof(RejuvenateSystem))]
     public sealed class RejuvenateTest
     {
         private const string Prototypes = @"
@@ -42,6 +43,7 @@ namespace Content.IntegrationTests.Tests.Commands
             var prototypeManager = server.ResolveDependency<IPrototypeManager>();
             var mobStateSystem = entManager.EntitySysManager.GetEntitySystem<MobStateSystem>();
             var damSystem = entManager.EntitySysManager.GetEntitySystem<DamageableSystem>();
+            var rejuvenateSystem = entManager.EntitySysManager.GetEntitySystem<RejuvenateSystem>();
 
             await server.WaitAssertion(() =>
             {
@@ -78,7 +80,7 @@ namespace Content.IntegrationTests.Tests.Commands
                 });
 
                 // Rejuvenate them
-                RejuvenateCommand.PerformRejuvenate(human);
+                rejuvenateSystem.PerformRejuvenate(human);
 
                 // Check that it is alive and with no damage
                 Assert.Multiple(() =>