Configurable prometheus queries

Kafka JMX metrics exported to Prometheus can have a very diverse representation and different calculation approaches (i.e.: promql avg vs jmx pre-calculated mean)

#1366 did a great job introducing the prometheus client however it is not flexible enough to make cruise control adoption less intrusive mainly for already running production clusters, as a common representation / pattern of the jmx metrics follows the example of the jmxexporter project which does not match the provided default queries.

#1366 also adds a nicely extension for providing a query supplier class, however the cruise configuration is not forward what makes complicated to access / add extra properties (i.e: properties file containing all the queries)

I would like to propose a new prometheus query supplier where the queries are extenalised to a properties configuration file.

I have made a simple test, by using the RawMetricType as key and the jmx_exporter example queries as values together with a small change to make the query supplier CruiseControlConfigurable and it works nicely.

Please let me know if you have any concerns/suggestions. If this solution brings value i would be more than happy to polish the code and create a PR in the following days.