Java System Properties not documented

Accumulo allows the user to modify the behavior of the runtime via Java System properties, but these are not documented anywhere. I found the following:

In CompressionAlgorithm.java, introduced into 2.1.0 via #2518 , the code allows the user to specify a different class name for the different compression algorithms. The value passed in for the property name is the value specified by the `getCodecClassNameProperty` method in the subclasses of `CompressionAlgorithmConfiguration`. For example, in 2.1 these are currently `io.compression.codec.bzip2.class`, `io.compression.codec.lz4.class`, `io.compression.codec.lzo.class`, `io.compression.codec.snappy.class`, and `io.compression.codec.zstd.class`.

https://github.com/apache/accumulo/blob/3ec800b9b9225e1b2d31efb9cd269c6c72666ef1/core/src/main/java/org/apache/accumulo/core/file/rfile/bcfile/CompressionAlgorithm.java#L292-L294

Other system properties are being used in SiteConfiguration and one is being introduced into 3.1 via https://github.com/apache/accumulo/pull/4880.

Start by reviewing CompressionAlgorithm.java, especially getCodecClassNameProperty and the referenced compression properties, then inspect SiteConfiguration and the system property introduced by pull request #4880. Identify the full set of runtime Java system properties and document each property's name and behavior in the project's documentation; done means users can find these properties in one place.

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