Property.isValidZooPropertyKey seems incorrect/outdated

There are several prefixes not defined in `isValidZooPropertyKey`, which I'm not sure is by design. For example, should `isValidZooPropertyKey` include any of `RPC_PREFIX`, `INSTANCE_PREFIX`, `MONITOR_PREFIX`, `COMPACTOR_PREFIX`, etc? It seems like `FIXED_PROPERTIES` is meant to be a subset of those that are `isValidZooPropertyKey` (see descriptions for `isFixedZooPropertyKey` and `isValidZooPropertyKey`). However, there are several cases of a fixed property which would not be `isValidZooPropertyKey` (e.g., `COMPACTOR_PORTSEARCH` is in `FIXED_PROPERTIES` but would return false for `isValidZooPropertyKey`). Either
1) At least one description is incorrect and should be updated
2) `isValidZooPropertyKey` is missing some prefixes and should be updated

2 seems most likely

_Originally posted by @kevinrr888 in https://github.com/apache/accumulo/pull/5632#pullrequestreview-2917620497_

Locate the definitions and descriptions of isValidZooPropertyKey, isFixedZooPropertyKey, FIXED_PROPERTIES, and the referenced prefixes. First compare the documented relationship with the current prefix lists and usages. Done means the descriptions and validation behavior agree for cases such as COMPACTOR_PORTSEARCH, with coverage for the resolved behavior.

Written by the indexing model from the issue text.