enhance faces content item so that it can be configured for row count and column count. also improve its css and pager

#241814. Allow members to see the subscription form for a private group (if group has open or moderated membership request handling).

rework how we emit the mission statement. requires a minor change to any site that themes theme_og_mission

#230501. Add hook_og_link_alter() where modules can fiddle with links in the og details block. Also add a link back to group homepage in block title.

fix #231901 in a different manner which might actually work. also simplified some code. ->og_groups_names no longer exists so that mighto break some custom themes. just use the new ->og_groups_both instead.