CaS: reflect changes in 'ranges' usage, update RPC API and Lua API

Summary

• cas: update ranges behavior
• api.md: remove create_table and drop_table (legacy)
• api.md: adjust examples to better match our test tables (legacy)

• Close #352 (closed)
• Cherry-pick to: 24.5
• Staging: https://docs.binary.picodata.io/picodata/at_cas/architecture/rpc_api/

Legacy Lua API page (not in nav) also updated:

https://docs.binary.picodata.io/picodata/at_cas/reference/api/