Make map tests more fine-grained. (#42977)

* Make map tests more fine-grained.

* ..typo.

* fix example

* exclude Empty.

* Adjust a scrounger test & fix it.

* It does respect ignored prototypes, after I realized making it do so was really easy.

* Fix it for real this time.

* General scrounger enhancements for a GameRules test set.

* Fix linter for real.

* Address reviews.

Content.YAMLLinter/Program.cs

@@ -4,6 +4,7 @@ using System.Linq;
 using System.Reflection;
 using System.Threading.Tasks;
 using Content.IntegrationTests;
+using Content.IntegrationTests.Utility;
 using Robust.Shared.Prototypes;
 using Robust.Shared.Reflection;
 using Robust.Shared.Serialization.Markdown.Validation;
@@ -17,6 +18,7 @@ namespace Content.YAMLLinter
     {
         private static async Task<int> Main(string[] _)
         {
+            GameDataScrounger.NoScrounging = true; // Ugly hack for YAML Linter.
             PoolManager.Startup();
             var stopwatch = new Stopwatch();
             stopwatch.Start();