[PM-12642] Add new ExtendedCache to add caching to template parameters (#6608)

* Add new ExtendedCache to add caching to template parameters

* Added Cache constants for building consistent keys/name, clarified that we are using defaults including TTL, removed as much fusion cache references as possible

src/Core/AdminConsole/Utilities/IntegrationTemplateProcessor.cs

@@ -1,6 +1,4 @@
-#nullable enable
-
-using System.Text.RegularExpressions;
+using System.Text.RegularExpressions;
 
 namespace Bit.Core.AdminConsole.Utilities;