sql: support '{abc}' syntax for uuid[] literal

[dt]

pg supports (and, importantly, emits) uuid[] literals in the form '{abc123-abc...}'

Cockroach currently does not, simply complaining that it is a string, since we do not implicitly convert the string to uuid[], though appending an explicit cast works (e.g. '{abc123-...}'::uuid[]).

Appending a cast or using the ARRAY[...] syntax provide alternatives for users writing queries by hand, but unfortunately some tools, like pg_dump emit the '{abc...}' form.

[jordanlewis]

Duplicate of #54672