Improves layout of to do items

app/assets/javascripts/pages/dashboard/todos/index/todos.js

app/assets/stylesheets/page_bundles/todos.scss

app/graphql/types/todo_action_enum.rb

app/helpers/markup_helper.rb

app/helpers/todos_helper.rb

app/views/dashboard/todos/_todo.html.haml

doc/api/graphql/reference/index.md

doc/user/todos.md

ee/spec/features/epics/update_epic_spec.rb

ee/spec/helpers/markup_helper_spec.rb

locale/gitlab.pot

...verify/system_cancel_merge_request_in_merge_train_spec.rb

spec/features/dashboard/todos/todos_filtering_spec.rb

spec/features/dashboard/todos/todos_spec.rb

spec/frontend/pages/dashboard/todos/index/todos_spec.js

spec/helpers/markup_helper_spec.rb

spec/helpers/todos_helper_spec.rb