Need an option to allow for SQL functions with qualified names

[seancorfield]

Is your feature request related to a problem? Please describe.
Some databases support qualified names for tables and columns, but
the current friendly SQL functions all use safe-name which
unconditionally drops the namespace.

Describe the solution you'd like
An option to allow for SQL functions to produce qualified names.

Describe alternatives you've considered
None.

Additional context
Specifically this affects working with XTDB via next.jdbc.xt.

[seancorfield]

Added :name-fn -- deliberately only documented in the CHANGELOG and All The Options pages to avoid over-complicating the main documentation, given that this is a fairly esoteric requirement (XTDB is the only database that has seemed to need this so far, but it's possible other users have databases with / in table and/or column names.

[seancorfield]

Since XTDB no longer accepts / in SQL names, there's no point in this additional complexity so I'm going to retire it.