Adds GitHub-like pages to view watched repos and subscribed issues/PRs This is my second try to fix this, but it is better than the first since it doesn't uses a filter option which could be slow when accessing `/issues` or `/pulls` and it shows both pulls and issues (the first try is #17053). Closes #16111 Replaces and closes #17053  Co-authored-by: Lauris BH <[email protected]> Co-authored-by: 6543 <[email protected]> Co-authored-by: wxiaoguang <[email protected]>