[DISCUSS] WIP pull request for CASSANDRA-17773

["Claude Warren, Jr via dev" <de...@cassandra.apache.org>]

Greetings,

I have created a pull request [1] as a work in progress for CASSANDRA-17773.

The idea here is to move the boiler plate include of cassandra.in.sh and
cassandra-env.sh into one sourced script that also provides a function
(verify_env) to verify that required variables are set.

verify_env  will also display the value of the required and other requested
vars if the ENV_DEBUG environment var is set.

Documentation can be found in the cassandra-conf.sh file.
Example usage is provided in the modified nodetool script.

Please let me know if this seems like a good response to the issues from
CASSANDRA-17773

If this seems appropriate then my plan is to modify the other scripts in
the /bin directory to utilize the cassandra-conf.sh script.

Claude

[1] https://github.com/apache/cassandra/pull/1950