Split UserCard into FollowCard/FollowRequestCard and Rewrite FollowList using HOCs

Closes #398 (closed)

I've split the current UserCard component into two based on its purpose (following/unfollowing user or accepting/rejecting follow request). Based on that, I've redefined the FollowList component using component composition technique with HOCs and the FollowCard component.

To make FollowCard and BlockCard consistent visually, I've added minor css changes.

Screenshots:

• FollowList

• FollowRequestList

• BlockList