Support data affinity schedule for performance optimization

[lcwangchao]

Background

See the background part in TiKV.

Tasks

TiDB

• ddl: support to set and alter the AFFINITY for table #64988
• ddl: sync affinity group for pd and support show affinity #65049
• meta,ddl: support must-load filtering for affinity #66627
• The affinity compatibility with BR / PiTR
• The affinity compatibility with CDC
• After truncate table, the affinity should also work.
• The affinity should also be handled after the exchange partition
• After truncate / drop table, the affinity group in PD should be GC after safepoint.
• recover table should handle AFFINITY
• flashback cluster should handle AFFINITY

TiKV

See: tikv/pd#9764

Release-8.5

• *: cherry-pick the table affinity to release-8.5 #65101