'bp' cache group cleanup

[johnjamesjacoby]

Back when BuddyPress was a wee little plugin, we used the bp global cache group for everything.

Now that BuddyPress is all grown up and we have more query complexity requiring more cached data, we can afford to introduce more appropriate cache groups for each component and purpose.

This will be a master ticket for ongoing cache group adjustments in 2.3.

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From #6114:

For example

• The entire Blogs component uses this group, instead of its own bp_blogs group.
• bp_activity_sitewide_front uses bp rather than bp_activity
• Friends uses bp for member relationships.
• Groups uses bp for total group counts and user memberships.
• XProfile uses bp for groups and visibility levels.

I think most of these would benefit from having/using their own global cache group.

[johnjamesjacoby]

In 9676:

XProfile: Introduce bp_xprofile_groups cache group, to replace bp cache group usage.

• Reduces field group cache keys down to just their ID, using a unique cache group
• Use all key instead of 'xprofile_groups_inc_empty`
• Use default_visibility_levels key instead of xprofile_default_visibility_levels

See #6341, #5733.

[r-a-y]

Marked #6114 as a duplicate and have copied the relevant ticket info to this ticket description.

[DJPaul]

We're closing this ticket because it has not received any contribution or comments for at least two years. We have decided that it is better to close tickets that are good ideas, which have not gotten (or are unlikely to get) contributions, rather than keep things open indefinitely. This will help us share a more realistic roadmap for BuddyPress with you.

Everyone very much appreciates the time and effort that you spent sharing your idea with us. On behalf of the entire BuddyPress team, thank you.

If you feel strongly that this enhancement should still be added to BuddyPress, and you are able to contribute effort towards it, we encourage you to re-open the ticket, or start a discussion about it in our Slack channel. Please consider that time has proven that good ideas without contributions do not get built.

For more information, see ​https://bpdevel.wordpress.com/2018/01/21/our-awaiting-contributions-milestone-contains/
or find us on Slack, in the #buddypress channel: ​https://make.wordpress.org/chat/