Add "Registry" folders as scan folders (#4583)

* Add "Registry" folders as scan folders

For projects, Gems, and Engine, add the "Registry" folder as scan
folders.

Signed-off-by: amzn-phist <52085794+amzn-phist@users.noreply.github.com>

* Change params for adding scan folder

Also add trailing newlines to setreg files.

Signed-off-by: amzn-phist <52085794+amzn-phist@users.noreply.github.com>

* Adjust the priority order for project templates

Scan folder orders were way too high, they should be very low to become
highest priority order.

Signed-off-by: amzn-phist <52085794+amzn-phist@users.noreply.github.com>

* Removes change of default assets folder to Assets

Need to revert this change so it can be done separately.
Renamed the scan folder to 'Project/Assets' to prep for Assets folder
change later on.

Signed-off-by: amzn-phist <52085794+amzn-phist@users.noreply.github.com>

* Update platform configuration test to pass

Adjusted expectation of scan folder count from 1 to 2 per Gem for
'Assets' and 'Registry' now.

Signed-off-by: amzn-phist <52085794+amzn-phist@users.noreply.github.com>

Code/Framework/AzFramework/AzFramework/Gem/GemInfo.h

@@ -29,6 +29,10 @@ namespace AzFramework
         AZStd::vector<AZ::IO::Path> m_absoluteSourcePaths; //!< Where the gem's source path folder are located(as an absolute path)
 
         static constexpr const char* GetGemAssetFolder() { return "Assets"; }
+        static constexpr const char* GetGemRegistryFolder()
+        {
+            return "Registry";
+        }
     };
 
     //! Returns a list of GemInfo of all the gems that are active for the for the specified game project.