Enable MA0054 and fix noncompliance

"Embed the caught exception as innerException"

Common.ruleset

@@ -270,7 +270,7 @@
 		<Rule Id="MA0053" Action="Hidden" />
 
 		<!-- Embed the caught exception as innerException -->
-		<Rule Id="MA0054" Action="Hidden" />
+		<Rule Id="MA0054" Action="Error" />
 
 		<!-- Do not use finalizer -->
 		<Rule Id="MA0055" Action="Hidden" />

src/BizHawk.Client.Common/XmlGame.cs

@@ -90,9 +90,9 @@ namespace BizHawk.Client.Common
 									data = File.ReadAllBytes(fullPath.Split('|').First());
 								}
 							}
-							catch
+							catch (Exception e)
 							{
-								throw new Exception($"Couldn't load XMLGame LoadAsset \"{filename}\"");
+								throw new Exception($"Couldn't load XMLGame LoadAsset \"{filename}\"", e);
 							}
 						}