revised UI color system when showing nodes

Olive now has a set of colors that categories can be "assigned" to. The timeline also shares the same colors as the NodeView. Colors can be configured per node (aka per clip).

app/widget/menu/menushared.cpp

@@ -86,9 +86,18 @@ MenuShared::MenuShared()
   view_timecode_view_milliseconds_item_->setCheckable(true);
   frame_view_mode_group_->addAction(view_timecode_view_milliseconds_item_);
 
+  // Color coding menu items
+  color_coding_menu_ = new ColorLabelMenu();
+  connect(color_coding_menu_, &ColorLabelMenu::ColorSelected, this, &MenuShared::ColorLabelTriggered);
+
   Retranslate();
 }
 
+MenuShared::~MenuShared()
+{
+  delete color_coding_menu_;
+}
+
 void MenuShared::CreateInstance()
 {
   instance_ = new MenuShared();
@@ -137,6 +146,11 @@ void MenuShared::AddItemsForInOutMenu(Menu *m)
   m->addAction(inout_clear_inout_item_);
 }
 
+void MenuShared::AddColorCodingMenu(Menu *m)
+{
+  m->addMenu(color_coding_menu_);
+}
+
 void MenuShared::AddItemsForClipEditMenu(Menu *m)
 {
   m->addAction(clip_add_default_transition_item_);
@@ -271,6 +285,11 @@ void MenuShared::TimecodeDisplayTriggered()
   Core::instance()->SetTimecodeDisplay(display);
 }
 
+void MenuShared::ColorLabelTriggered(int color_index)
+{
+  PanelManager::instance()->CurrentlyFocused()->SetColorLabel(color_index);
+}
+
 void MenuShared::Retranslate()
 {
   // "New" menu shared items