Add option to make shader search paths non-recursive

* For very large shader symbol stores especially those on network drives, the
  bad behaviour that PIX has to recursively search all possible subdirectories
  and enumerate all files can be really slow. Most of the time a file is
  identified by its hash filename and looked up directly - if that isn't a hit,
  in many cases users would rather a fast exit to having no symbols.

qrenderdoc/Code/Interface/PersistantConfig.cpp

@@ -303,18 +303,6 @@ void PersistantConfig::applyValues(const QVariantMap &values)
           debug->AddAndOwnChild(makeSDString("$el"_lit, searchPaths[i]));
       }
 
-      if(settings.contains(lit("d3d12ShaderDebugging")))
-      {
-        RENDERDOC_SetConfigSetting("D3D12_ShaderDebugging")->data.basic.b =
-            settings[lit("d3d12ShaderDebugging")].toBool();
-      }
-
-      if(settings.contains(lit("vulkanShaderDebugging")))
-      {
-        RENDERDOC_SetConfigSetting("Vulkan_ShaderDebugging")->data.basic.b =
-            settings[lit("vulkanShaderDebugging")].toBool();
-      }
-
       saveConfig = true;
     }