[ACA-4712] disallow using important for styles (#3368)

* ACA-4712 Added rule to prevent using important for styles

* ACA-4712 Removed important from some global styles and from manage rule component

* ACA-4712 Removed important from rest global and theme styles

* ACA-4712 Removed usages of important from styles for components

.stylelintrc.json

@@ -9,6 +9,7 @@
       {
         "resolveNestedSelectors": true
       }
-    ]
+    ],
+    "declaration-no-important": true
   }
 }