Move jquery-minicolors to npm/webpack (#12305)

* Move jquery-minicolors to npm/webpack

- Unvendor and add as npm dependency
- Removed unneeded backend variable
- Fixed existing bug where picker would previously initizalize to the
  same green color when editing a label.

There was probably a version bump because the previous version was
over 3 years old but it seems to be compatible.

* use file-loader

* trailing comma and comment update

* misc tweaks

Co-authored-by: Lauris BH <lauris@nix.lv>
Co-authored-by: techknowlogick <techknowlogick@gitea.io>

package.json

@@ -10,6 +10,7 @@
     "@babel/plugin-transform-runtime": "7.10.5",
     "@babel/preset-env": "7.10.4",
     "@babel/runtime": "7.10.5",
+    "@claviska/jquery-minicolors": "2.3.5",
     "@primer/octicons": "10.0.0",
     "babel-loader": "8.1.0",
     "clipboard": "2.0.6",