feat: add support for LightOnOCR-2-1B (#3213)

feat: add support for LightOnOCR-2-1B VLM model

Add LightOnOCR-2-1B as a new VLM model option for OCR and markdown conversion.
Includes transformers, vLLM, and API configurations, stage model preset,
and tests.

Signed-off-by: Georg Heiler <georg.kf.heiler@gmail.com>