Add limits for kanban boards (#234)

Prevent dropping a task onto a bucket which has its limit reached

Fix closing the dropdown

Add notice to show the limit

Add input to change kanban bucket limit

Add menu item to save bucket limit

Fix parsing dates from the api

Co-authored-by: kolaente <k@knt.li>
Reviewed-on: https://kolaente.dev/vikunja/frontend/pulls/234

src/services/taskComment.js

@@ -14,8 +14,8 @@ export default class TaskCommentService extends AbstractService {
 	}
 
 	processModel(model) {
-		model.created = formatISO(model.created)
-		model.updated = formatISO(model.updated)
+		model.created = formatISO(new Date(model.created))
+		model.updated = formatISO(new Date(model.updated))
 		return model
 	}