Add Tailwind button for save+cancel

- remove custom styles
- add new button styles based on Tailwind classes using @apply
- extend config to allow hover:ring-blue-200 and such
- update the js-files to use new classes

- Only unsure about the `.review-form .save-non-active`, this might need additional Tailwind helper classes in this specific situation. Don't know where it shows up, so could not test.

css/ReviewElement.css

@@ -114,9 +114,6 @@
     display: block ruby;
 }
 
-.review-form .save-non-active {
-    display: block ruby;
-}
 .review-form textarea {
     resize: unset;
 }