Register Presto-specific Velox cuDF functions in native startup

[firestarman]

Problem

Velox has separate registration paths for common cuDF functions and Presto-specific cuDF functions:

velox::cudf_velox::registerCudf();
velox::cudf_velox::registerPrestoFunctions(...);

Presto native currently initializes cuDF by calling velox::cudf_velox::registerCudf(), but it does not call velox::cudf_velox::registerPrestoFunctions() in the cuDF startup path.

As a result, Presto-specific cuDF functions are not registered when cuDF is enabled in Presto native.

Proposed fix

Call registerPrestoFunctions() after registerCudf() in registerVeloxCudf(), using the configured cuDF function name prefix:

velox::cudf_velox::registerCudf();
velox::cudf_velox::registerPrestoFunctions(
    velox::cudf_velox::CudfConfig::getInstance().functionNamePrefix);

This keeps the Presto-specific cuDF registration next to the existing cuDF initialization and preserves the configured Presto function namespace.

Context

A small PR with the proposed change was opened here for reference, but could not proceed because of CLA authorization on the submitter account:

• fix(native): register Presto cuDF functions #28056