Rewrite all Promises to use async/await syntax in src/client/components/pages

Files requiring changes :

1. collection.js - https://github.com/metabrainz/bookbrainz-site/blob/master/src/client/components/pages/collection.js

2. revision.js - https://github.com/metabrainz/bookbrainz-site/blob/master/src/client/components/pages/revision.js

3. add-entity-to-collection-modal.js - https://github.com/metabrainz/bookbrainz-site/blob/master/src/client/components/pages/parts/add-entity-to-collection-modal.js

4. add-to-collection-modal.js - https://github.com/metabrainz/bookbrainz-site/blob/master/src/client/components/pages/parts/add-to-collection-modal.js

5. delete-or-remove-collaboration-modal.js - https://github.com/metabrainz/bookbrainz-site/blob/master/src/client/components/pages/parts/delete-or-remove-collaboration-modal.js

6. wikipedia-extract.tsx - https://github.com/metabrainz/bookbrainz-site/blob/master/src/client/components/pages/entities/wikipedia-extract.tsx