[Subtask]: User defined Scalar Function

### Parent Issue

#6581

### Detail of Subtask

User defined scalar function -- this is relatively straightforward. UDF takes a list of arguments return one value per call.

Note that the impl. can/should be vectorized, that is, each call from CN to UDF server pass in a batch, and result returned in a batch (or vector).

### Describe implementation you've considered

_No response_

### Additional information

_No response_