Adds Inspector to Gem Repo Screen (#4242)

* Adds the gem repo screen with the UI built but with mocked data and not connected to the o3de scripts

Signed-off-by: nggieber <nggieber@amazon.com>

* Changed name of added to enabled, disabled define, removed unused functions

Signed-off-by: nggieber <nggieber@amazon.com>

* Added Repo Screen Inspector UI

Signed-off-by: nggieber <nggieber@amazon.com>

* Addressed minor PR feedback

Signed-off-by: nggieber <nggieber@amazon.com>

* Add some more minor PR changes

Signed-off-by: nggieber <nggieber@amazon.com>

Code/Tools/ProjectManager/Source/GemRepo/GemRepoListView.h

@@ -10,6 +10,7 @@
 
 #if !defined(Q_MOC_RUN)
 #include <QListView>
+#include <QItemSelectionModel>
 #endif
 
 QT_FORWARD_DECLARE_CLASS(QAbstractItemModel)
@@ -22,7 +23,7 @@ namespace O3DE::ProjectManager
         Q_OBJECT // AUTOMOC
 
     public:
-        explicit GemRepoListView(QAbstractItemModel* model, QWidget* parent = nullptr);
+        explicit GemRepoListView(QAbstractItemModel* model, QItemSelectionModel* selectionModel, QWidget* parent = nullptr);
         ~GemRepoListView() = default;
     };
 } // namespace O3DE::ProjectManager