fix: Support Vortex byte-vector list input (#50110)

issue: #49828

## What changed

This PR accepts UInt8 List and FixedSizeList Arrow input for BF16 and
binary vector fields when the list length matches the raw byte width.

It keeps non-UInt8 byte-vector list input rejected, keeps width mismatch
validation, and enables the Vortex full-matrix E2E case for `bf16v`,
`binv_flat`, and `binv_ivf`.

## Why

Vortex writes BF16 and binary vector payloads as UInt8 list values
because
it cannot persist them as FixedSizeBinary. Milvus previously rejected
those
list encodings, so Vortex external tables could not cover BF16 and
binary
vector fields.

## Validation

- `make milvus`
- `all_tests --gtest_filter='NormalizeExternalArrow.*'`
- `all_tests --gtest_filter='NormalizeVectorArraysToFixedSizeBinary.*'`
- `python3 -m py_compile
tests/python_client/milvus_client/test_milvus_client_external_table.py`
- `make lint-fix`
- `git diff --check --cached`
- `pytest milvus_client/test_milvus_client_external_table.py -k
test_milvus_client_external_table_full_matrix_vortex`

---------

Signed-off-by: Wei Liu <wei.liu@zilliz.com>