kvcoord: condense read spans when they exceed the memory limit

[jseldess]

Jesse Seldess commented:

PR: cockroachdb/cockroach#46275

From release notes:

Transactions reading a lot of data behave better when exceeding the memory limit set by kv.transaction.max_refresh_spans_bytes. Such transactions now attempt to resolve the conflicts they run into instead of being forced to always retry. Increasing kv.transaction.max_refresh_spans_bytes should no longer be necessary for most workloads. [#46275][#46275] {% comment %}doc{% endcomment %}

See also:

• kv: add guidance for kv.transaction_max_refresh_span_bytes #7012 kv: add guidance for kv.transaction_max_refresh_span_bytes

Jira Issue: DOC-544