Fixes #4615: OpenRA.Utility should expand wildcards in paths

The path to be expanded. It can be a relative or an absolute path.
Wildcards can appear as part of the path and as part of the file name/extension.

Example:

	Expand("./mods/*/mod.?aml");

OpenRA.Utility/OpenRA.Utility.csproj

@@ -79,6 +79,7 @@
     <Compile Include="Program.cs" />
     <Compile Include="UpgradeRules.cs" />
     <Compile Include="LegacyMapImporter.cs" />
+    <Compile Include="Glob.cs" />
   </ItemGroup>
   <ItemGroup>
     <ProjectReference Include="..\OpenRA.Game\OpenRA.Game.csproj">