Allow passing environment variables to Reaper

[a-mroz]

Is your feature request related to a problem? Please describe.
I'm trying to deploy Cassandra 5 with Reaper. Unfortunately, Reaper cannot start, due to Unknown function dateof called error.

I'd like to try the workaround described here, but there seems to be no way of passing environment variables to Reaper (at least documented in the docs).

Describe the solution you'd like
Expose env for reaper, similarly to what Cassandra has.

┆Issue is synchronized with this Jira Story by Unito
┆Issue Number: K8OP-290

[a-mroz]

For this particular case (REAPER_SKIP_SCHEMA_MIGRATION), I found that there's an option skipSchemaMigration defined in Reaper.spec, however it's not defined in K8ssandraCluster.spec.reaper.