[Improvement] Redis Cluster content format should be handled robustly during upgrade

[im0x0ing]

Problem
When upgrading to KubeBlocks 0.9, existing Redis Cluster resources have a content format that is incompatible with KB 0.9.

Current Workaround
A migration script is executed manually during the upgrade to convert Redis Cluster content to the KB 0.9 compatible format.

Expected Behavior
The upgrade code should be able to validate and automatically convert the Redis Cluster content format when encountering incompatible formats, rather than relying on external scripts.