Add a compaction CassandraTask

[adejanovski]

What is missing?

We would need to give the ability to perform compactions using a CassandraTask.
It would perform the equivalent of a "nodetool compact" command, but through the management api.
This task would need to be configurable so it can run either sequentially or in parallel, and target specific nodes/pods only.

Definition of Done

Beta Give feedback

1. A CassandraTask command to support a compaction operation is added
2. That command can take a keyspace and a table as arguments
3. This CassandraTask can optionnally target specific nodes

Why is this needed?

Compaction is a common operation when managing Cassandra clusters, and we want to have a more Kubernetes native way of scheduling them, without requiring to run nodetool from within the containers.