Made a mass of accessibility improvements

- Changed default focus styles
- Updated dropdowns with keyboard navigation
- Updated modals with esc exiting
- Added accessibility attirbutes where needed
- Made many more elements focusable
- Updated hover effects of many items to also apply when focused within

Related to #1320 and #1198

resources/views/components/image-manager.blade.php

@@ -9,7 +9,7 @@
     ])
 
     <div overlay v-cloak @click="hide">
-        <div class="popup-body" @click.stop="">
+        <div class="popup-body" tabindex="-1" @click.stop>
 
             <div class="popup-header primary-background">
                 <div class="popup-title">{{ trans('components.image_select') }}</div>