appview: implement follower and following pages for users
- rename Followers/Following from ProfileCard to FollowersCount/FollowingCount
- in profileCard, define a single $userIdent to use instead of duplicating the didOrHandle expression
fixes https://tangled.sh/@tangled.sh/core/issues/169
Signed-off-by: dusk <y.bera003.06@protonmail.com>