Unify badges across the site

• Use badge-pill for all badges. Badge-pill adds padding which is required due to our border-radius value.
• Remove undefined css classes from team_member_associate.html include file
• Replace custom labels by the same badges on post metadata
• Add icons to post metadata

@hueser93 @erxleb87 IF we agree on merging this, should I also remove the now unused labels css classes?