chore: Prepare CRD versioning

[Techassi]

Part of stackabletech/issues#808.

This prepares the operator for future CRD versioning by adding a conversion webhook and maintaining the CRD(s) on its own.

Smoke tests passed:

--- PASS: kuttl (945.04s)
    --- PASS: kuttl/harness (0.00s)
        --- PASS: kuttl/harness/smoke_trino-477_hive-3.1.3_opa-1.12.3_hdfs-3.4.2_zookeeper-3.9.4_openshift-false (449.44s)
        --- PASS: kuttl/harness/smoke_trino-479_hive-3.1.3_opa-1.12.3_hdfs-3.4.2_zookeeper-3.9.4_openshift-false (468.27s)
        --- PASS: kuttl/harness/smoke_trino-479_hive-4.2.0_opa-1.12.3_hdfs-3.4.2_zookeeper-3.9.4_openshift-false (470.49s)
        --- PASS: kuttl/harness/smoke_trino-477_hive-4.2.0_opa-1.12.3_hdfs-3.4.2_zookeeper-3.9.4_openshift-false (476.16s)
PASS

Release Note

• The operator now maintains its own CRD(s) instead of relying on Helm as a deployment mechanism. Additionally, the conversion webhook is now running alongside the controller for future CRD versioning.