* [LYN-2515] Project Manager Gem List Base
* Added gem model based on a standard item model
* Added list view using the gem model
* Added item delegate for a gem according to the UX design
* Removed th gem catalog ui file and replaced it with code
* Moved the gem catalog files into a sub folder
* Added drawing the Added/Get button and the platform icons
* Created the Project Manager project with a barebone styled window and rough sketch of first screen
* Renamed to Project Manager, ect.
* Corrected string name for projectmanager and added comments on getting engine path
* Changed output name for Project Manager to lowercase o3de
* Added header guards