[TC] [OBJCLI] Incomplete support for object versioning

What's the issue?
Object versioning support in 'objcli' is incomplete:

1. GCP/Azure support listing versions, where AWS silently ignores it
2. GCP/Azure have different types for versions (where AWS doesn't populate it) which results in runtime type assertions

This is a foot-gun as 'objcli' has undocumented - incomplete - support for object versions where the implication is that it's complete (based solely on the APIs).

What's the fix?
The core reason for us needing to support object versioning was when emptying (deleting) a bucket, so we should limit the impact to only that functionality and leave the rest as not supporting versions (as we don't).

Considerations
Unfortunately, this is likely to be a breaking change so a major version bump is required.