Convert some complex PriorityQueue implementations to comparators

[thecoop]

A 3rd set of PriorityQueue conversions. These ones are more controversial, and so need some specific review and discussion

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[github-actions]

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[github-actions]

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[thecoop]

The subclasses that are remaining after this PR are:

• TermsMergeQueue. This has some additional state in the stack variable
• FieldValueHitQueue. This is further subclassed, and is public (although experimental)
• HitQueue. Public class (although internal). Used in several difference places, so this class represents some common functionality.
• TopDocs.ScoreMergeSortQueue, TopDocs.MergeSortQueue. Has some significant state fields in them
• TopOrdAndNumberQueue and subclasses. Part of the public API, and has some abstract behavious set by subclasses
• SuggestWordQueue. Public API

[dweiss]

I like it. Please consider one rename and add a changes.txt entry - this is a significant change and cleanup, worth mentioning in the docs.