[v3] Implement store methods for erase and rename operations

[jhamman]

We have not yet implemented bulk erase (dir or prefix) or rename methods for the V3 store interface. These are both needed to support efficient evolution of existing zarr hierarchies. Marking this as a blocker for 3.0.

[jhamman]

We implemented erase (del_prefix) but we have not done anything for rename yet. That remains a TODO here.