Feature: Shopping List Label Section Improvements (#2090)

* added backend for shopping list label config

* updated codegen

* refactored shopping list ops to service
removed unique contraint
removed label settings from main route/schema
added new route for label settings

* codegen

* made sure label settings output in position order

* implemented submenu for label order drag and drop

* removed redundant label and tweaked formatting

* added view by label to user preferences

* made items draggable within each label section

* moved reorder labels to its own button

* made dialog scrollable

* fixed broken model

* refactored labels to use a service
moved shopping list label logic to service
modified label seeder to use service

* added tests

* fix for first label missing the tag icon

* fixed wrong mapped type

* added statement to create existing relationships

* fix restore test, maybe

frontend/lang/messages/en-US.json

@@ -603,6 +603,7 @@
     "copy-as-markdown": "Copy as Markdown",
     "delete-checked": "Delete Checked",
     "toggle-label-sort": "Toggle Label Sort",
+    "reorder-labels": "Reorder Labels",
     "uncheck-all-items": "Uncheck All Items",
     "check-all-items": "Check All Items",
     "linked-recipes-count": "No Linked Recipes|One Linked Recipe|{count} Linked Recipes",