Fixes #13044

Problem

When sending a PATCH request that only updates metadata fields (like description or title) on a SingleSelect/MultiSelect column without including colOptions, the existing dropdown options get lost.

This happens because the SingleSelect/MultiSelect code path in columnUpdate checks colBody.colOptions?.options to decide whether to process the options block. When colOptions isn't provided, the entire block is skipped -- which means either:

• The metadata update is silently dropped (no Column.update or updateMetaAndDatabase call happens)
• In certain flows, Column.update deletes the existing options but doesn't re-insert them since there are none in colBody

This is the same class of bug that was fixed for cdf in #12974.

Fix

After calling getColumnPropsFromUIDT, check if colBody.colOptions?.options is missing but the existing column has options. If so, carry over the existing options to colBody. This way the full update flow proceeds normally, the options are preserved, and metadata-only changes (description, title, etc.) are actually applied.

Reproduction

# Create a SingleSelect column with options, then:
curl -X PATCH \
  'https://<nocodb>/api/v2/meta/columns/<column_id>' \
  -H 'xc-token: <token>' \
  -H 'Content-Type: application/json' \
  -d '{"description": "some description"}'

# Before fix: colOptions wiped / description update silently dropped
# After fix: colOptions preserved, description updated