Allow allocating a new top level key with prefixed id for the KKV data store

[jbirddog]

Stems from discussions with @calexh-sar - in the IRB prototype for example it would be nice for the top level key in a kkv data store to be study_123 - but how to atomically get the next id to use as the top level key before insertion of the record? If a new script was added that allowed for something like new_id = allocate_kkv_top_level_key("study_") then it could safely be done by using the id of the newly inserted row, which would contain minimal placeholder information. Exact syntax is not defined.

[jbirddog]

Confirmed with @calexh-sar that this is working.

[madhurrya]

@calexh-sar @usama9500 Is this already documented? Shall I close this?

[calexh-sar]

I defer to @usama9500 if this has been documented.

[usama9500]

The exact use case is not documented, but KKV data store is documented here: #1360

You can leave it open, I will discuss with @jbirddog on the exact information to be added.