Removed absolute positioning from TitleBar

MaterialGraphProject/Assets/GraphFramework/SerializableGraph/Editor/Drawing/Styles/TitleBar.uss

 #TitleBar {
-    position-type: absolute;
-    position-left: 0;
-    position-right: -1;
-    position-top: -1;
+    background-color: #212121;
+    padding-bottom: 1;
+    padding-left: 1;
+}
+
+#TitleBar #left,
+#TitleBar #right {
-    border-width: 1;
-    border-left: 1;
-    border-right: 1;
-    border-top: 1;
-    border-bottom: 1;
-    border-color: #212121;
+    flex: 1;
 }
 
 #TitleBar #left {