Change the format of sync points to use host ID instead of IPs, to be consistent with the use of host IDs in hinted handoff module.
Introduce sync point v3 format which is the same as v2 except it stores host IDs instead of IPs.
The decoding supports both formats with host IDs and IPs, so a sync point contains now a variant of either types, and in the case of new type the translation is avoided.
Fixes#18653Closesscylladb/scylladb#19134
* github.com:scylladb/scylladb:
db/hints: migrate sync point to host ID
db/hints: rename sync point structures with _v1 suffix to _v1_v2
0b5a0c969a