Add color indicators to task list (#321)

fix requested changes

use computed for listColor, moved .colorBubble to theme.scss

fixed tabs

add color indicator to task list

Reviewed-on: https://kolaente.dev/vikunja/frontend/pulls/321
Reviewed-by: konrad <konrad@kola-entertainments.de>
Co-Authored-By: Bouni <bouni@owee.de>
Co-Committed-By: Bouni <bouni@owee.de>

src/styles/components/tasks.scss

@@ -53,6 +53,11 @@
       display: none;
     }
 
+    .color-bubble {
+      width: 11px;
+      height: 10px;
+    }
+
     .tag {
       margin: 0 0.5em;
     }