Fix FilteredConnection input style

Created by: tjkandala

Fix #16268 (closed).

• Add inputClassName prop to FilteredConnection and remove current max-width 30%, which was only necessary for #16194
• Use useObservable for data fetching in UserSettingsRepositoriesPage. This ensures that we don't fetch once for each render until the Promise is fulfilled and sets fetched state to true. useObservable also takes care of cancellation and error handling

After fix