Switch ui/qt-creator to overlay convention

.orchestra/config/components.yml

 #@ load("@ytt:template", "template")
 #@ load("@ytt:data", "data")
 
-#@ load("/components/ui/qt_creator.lib.yml", "qt_creator_component")
 #@ load("/components/ui/graphviz.lib.yml", "graphviz_component")
 #@ load("/components/ui/adaptagrams.lib.yml", "adaptagrams_component")
 #@ load("/components/ui/cold_revng.lib.yml", "cold_revng_component")
@@ -25,7 +24,6 @@
 
 #@ load("/global_options.lib.yml", "options")
 components:
-  ui/qt-creator: #@ qt_creator_component
   ui/graphviz: #@ graphviz_component
   ui/adaptagrams: #@ adaptagrams_component
   ui/cold-revng: #@ cold_revng_component

.orchestra/config/components/ui/qt_creator.lib.yml → .orchestra/config/components/ui/qt_creator.yml

+#@ load("@ytt:overlay", "overlay")
 #@ load("/lib/make.lib.yml", "make")
 #@ load("/lib/shell.lib.yml", "expand_args")
 #@ load("/lib/optimization_flavors.lib.yml", "qmake_optimization_flavors")
@@ -62,6 +63,8 @@ builds:
   #@ end
 #@ end
 
+#@overlay/match by=overlay.all, expects=1
+#@overlay/match-child-defaults missing_ok=True
 ---
-
-#@ qt_creator_component = _qt_creator_component()
+components:
+  ui/qt-creator: #@ _qt_creator_component()