LRUQueryCache#doCache Should Be More Verbose [LUCENE-8946]

doCache does not really cache the query on its invocation. The actual caching (or checks) will happen only during scoring. doCache is basically creating the caching weight wrapper around the original weight of the query.

We should 1) rename the method or/and 2) update the documentation around the method explicitly calling out this facet.

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Migrated from [LUCENE-8946](https://issues.apache.org/jira/browse/LUCENE-8946) by Atri Sharma (@atris)

Locate LRUQueryCache#doCache and read its method documentation alongside the scoring path it wraps. Done means the method name or documentation clearly explains that caching checks occur during scoring rather than when doCache is invoked.

Written by the indexing model from the issue text.