Enabling static analysis on indexer plugin and fixing errors (#5220)

* Enabling code analysis, and treating warnings as errors

* Error CA1724 The type name Settings conflicts in whole or in part with the namespace name 'Microsoft.PowerToys.Settings'. Change either name to eliminate the conflict. Microsoft.Plugin.Indexer C:\repos\powertoys\src\modules\launcher\Plugins\Microsoft.Plugin.Indexer\Settings.cs 9 Active

* Removing keyword "Interface" from namespace to fix fxcop warnings

* Fixing static analysis warnings on ContextMenuLoader

* Fixing general exception warnings for static analysis

* Fixing public list variables, non static methods, and general exception warning

* Implementing IDisposable on OleDBSearch although in practice these objects were already being disposed.

Also Validated we were not using user input directly for sql strings.

* Removing VS generated comments from dispose methods as per PR feedback.

* Setting translated text to use current culture as per PR feedback.

* Explicity specifying 'internal' access modifier for Indexer 'Main' class, as per PR feedback

* Updating to FxCop 3.0.0

src/modules/launcher/Plugins/Microsoft.Plugin.Indexer/Interface/IRegistryWrapper.cs

@@ -2,7 +2,7 @@
 using System.Collections.Generic;
 using System.Text;
 
-namespace Microsoft.Plugin.Indexer.Interface
+namespace Microsoft.Plugin.Indexer
 {
     public interface IRegistryWrapper
     {

src/modules/launcher/Plugins/Microsoft.Plugin.Indexer/Interface/ISearch.cs

@@ -1,7 +1,7 @@
 using Microsoft.Plugin.Indexer.SearchHelper;
 using System.Collections.Generic;
 
-namespace Microsoft.Plugin.Indexer.Interface
+namespace Microsoft.Plugin.Indexer
 {
     public interface ISearch
     {