DataType enum: reads raise ValueError on five documented wire type IDs #829

Summary & Why It is important

Converter.get() resolves DataType(type_) before it can fall back to the default converter, so any column type identifier the enum doesn't list raises instead of passing the value through. Five documented IDs are missing:

1. 17 INTERVAL
2. 18 ROW
3. 28 FLOAT_VECTOR
4. 29 UUID
5. 30 REGTYPE.

Impact

FLOAT_VECTOR is the sharp edge. Critically, users who never touch converters still hit this, setting cursor.time_zone implicitly constructs a Converter, so a timezone-aware cursor breaks on a vector column. A plain cursor is unaffected, which makes it look config-dependent to users.

Reproduction

Verified against a live CrateDB 6.4.3. I derived all five IDs from the server rather than trusting the docs table:

All five fail on both the explicit-converter path and the time_zone=-only path. The plain-cursor control returns them fine.

Root cause

DataType(type_) is constructed to be used as a dict key, so an unlisted ID raises before self._default is reachable.