Restructure components

opentech/static_src/src/app/src/SubmissionsByRoundApp.js

...ech/static_src/src/app/src/components/DetailView/index.js

opentech/static_src/src/app/src/components/Listing/index.js

...tech/static_src/src/app/src/components/Listing/style.scss

opentech/static_src/src/app/src/components/ListingHeading.js

opentech/static_src/src/app/src/components/ListingItem.js

...tech/static_src/src/app/src/containers/ByStatusListing.js

...tic_src/src/app/src/containers/GroupByStatusDetailView.js

opentech/static_src/src/app/src/index.js

...ech/static_src/src/app/src/redux/selectors/submissions.js