Add test pooling (#4961)

* Add test pooling

* WIP test pooling changes

* Fix Destructible tests

* Don't pool unpooled or dummy ticker instances

* Change ServerPathfindingDebugSystem to replace existing entries

* Fix SaveLoadSaveTest comment

* Don't pool StartTest

* Comment out global setup

* Fix puddle tests

* Move SolarPanelComponent initialize to PowerSolarSystem OnMapInit

* Update RobustToolbox

* Finish fixing tests, make test threads background threads

* Bring back pooling

* Fix nullable

* Update RobustToolbox

* Set cvars on server return

* Un-pool tests with custom cvars

* Update RobustToolbox

* Update RobustToolbox

* Change where the main tile coordinates are

* Remove DisposalUnitTest grid check

* Fix test pooling being a fickle bitch

* Fix EntitySystemExtensionsTest

* Update RobustToolbox

* Update RobustToolbox

* Make nullable pool settings true

* Update RobustToolbox

* Wait other way around

* We are unitystation now

* Update RobustToolbox

* Create global setup

* Pool some more tests

* Fix not properly disconnecting clients before restarting the round

* Give more info on ran tests

* Standardize default test cvars

* Update RobustToolbox

* Update RobustToolbox

* Pool clients

* Fix test order issue

* Fix cvars in character creation test not being set properly

* Update RobustToolbox

* Update RobustToolbox

* Rider shut

* Update RobustToolbox

* Format tests ran better

* Update RobustToolbox

* Reset RobustToolbox

* Reset RobustToolbox harder

* Fix one instance of test order causing destructible tests to fail

Content.IntegrationTests/Tests/AI/BehaviorSetsTest.cs

@@ -7,7 +7,6 @@ using Content.Server.AI.Utility.AiLogic;
 using NUnit.Framework;
 using Robust.Shared.Prototypes;
 using Robust.Shared.Reflection;
-using YamlDotNet.RepresentationModel;
 
 namespace Content.IntegrationTests.Tests.AI
 {
@@ -18,8 +17,7 @@ namespace Content.IntegrationTests.Tests.AI
         [Test]
         public async Task TestBehaviorSets()
         {
-            var options = new ServerIntegrationOptions();
-            var server = StartServerDummyTicker(options);
+            var server = StartServer();
             await server.WaitIdleAsync();
 
             var protoManager = server.ResolveDependency<IPrototypeManager>();