Add test coverage for renaming viewless timeseries collections, and fix or document any issue that is found.

Note that rename has two different code paths that we should cover:

• Rename within a DB
• Rename across different databases

Rename across databases does a copy of the data - we should ensure this is done over buckets rather than individual measurements.

If rename across databases is nontrivial to support we may chose to return an error instead (since it isn't supported for legacy timeseries).