ExitableDirectoryReader slowdowns intensive points and terms query

[jimczi]

The exitable directory reader added in #52822 seems to slowdown queries that uses points (range queries) and terms dictionary (terms ad multi-term queries) intensively. These slowdowns have been spotted in our nightly runs as outlined here.
We open this issue to discuss the best ways to mitigate these slowdowns. The first thing we'd like to try is to make the interval at which we check for cancellation or timeout smaller since we started with a relatively low value (15).

[elasticmachine]

Pinging @elastic/es-search (:Search/Search)