Client properties file should be loaded using commons-configuration

The code for loading client props seems to use java Properties and not commons config, so FileHandler would not be applicable there. https://github.com/apache/accumulo/blob/cf42adff3f988ff467ff3f71449732b32703573f/core/src/main/java/org/apache/accumulo/core/clientImpl/ClientInfoImpl.java#L113

_Originally posted by @keith-turner in https://github.com/apache/accumulo/issues/5233#issuecomment-2576448056_

Start in core/src/main/java/org/apache/accumulo/core/clientImpl/ClientInfoImpl.java around line 113, where the client properties are loaded. Compare that loading path with commons-configuration and its FileHandler support; the work is done when client properties use the commons-configuration path described by the issue.

Written by the indexing model from the issue text.