Make gem tags clickable and filter by their text in the Gem Catalog when clicked

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

Code/Tools/ProjectManager/Source/GemsSubWidget.h

@@ -22,10 +22,15 @@ namespace O3DE::ProjectManager
     class GemsSubWidget
         : public QWidget
     {
+        Q_OBJECT // AUTOMOC
+
     public:
         GemsSubWidget(QWidget* parent = nullptr);
         void Update(const QString& title, const QString& text, const QStringList& gemNames);
 
+    signals:
+        void TagClicked(const QString& tag);
+
     private:
         QLabel* m_titleLabel = nullptr;
         QLabel* m_textLabel = nullptr;