Standardize on "recordset" (vs record-set)

[mdb]

Currently, vinyldns-cli features various record-set commands, which is arguably unfortunate, as "recordset" is one word & not hyphenated. It would be good to standardize on "recordset" and perhaps alias record-set commands to their recordset equivalents to preserve functionality for existing users. If this issue is pursued, a stretch goal is to offer users of record-set* commands some messaging about its deprecation and eventual removal in favor of the recordset equivalents.