Add Initial Gem Repository Management Screen (#4172)

* 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 eof nl to qss

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

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

@@ -0,0 +1,23 @@
+/*
+ * Copyright (c) Contributors to the Open 3D Engine Project.
+ * For complete copyright and license terms please see the LICENSE at the root of this distribution.
+ *
+ * SPDX-License-Identifier: Apache-2.0 OR MIT
+ *
+ */
+
+#include <GemRepo/GemRepoListView.h>
+#include <GemRepo/GemRepoItemDelegate.h>
+
+namespace O3DE::ProjectManager
+{
+    GemRepoListView::GemRepoListView(QAbstractItemModel* model, QWidget* parent)
+        : QListView(parent)
+    {
+        setObjectName("gemRepoListView");
+        setVerticalScrollMode(QAbstractItemView::ScrollPerPixel);
+
+        setModel(model);
+        setItemDelegate(new GemRepoItemDelegate(model, this));
+    }
+} // namespace O3DE::ProjectManager