token_range_vector is a sequence of intervals of tokens. It is used
to describe vnodes or token ranges owned by shards.
Since tokens are bloated (16 bytes instead of 8), and intervals are bloated
(40 byte of overhead instead of 8), and since we have plenty of token ranges,
such vectors can exceed our allocation unit of 128 kB and cause allocation stalls.
This series fixes that by first generalizing some helpers and then changing
token_range_vector to use chunked_vector.
Although this touches IDL, there is no compatibility problem since the encoding
for vector and chunked_vector are identical.
There is no performance concern since token_range_vector is never used on
any hot path (hot paths always contain a partition key).
Fixes#3335.
Fixes#24115.
No backport: minor performance fix that isn't a regression.
Closesscylladb/scylladb#24205
* https://github.com/scylladb/scylladb:
dht: fragment token_range_vector
partition_range_compat: generalize wrap/unwrap helpers
c21692f3a6