feat: add 2 stage model dowload from hf and call it for threaded layout model. (#3267)

* feat: add 2 stage model dowload from hf and call it from threaded_layout_vlm_pipeline

Signed-off-by: ElHachem02 <peterelhachem02@gmail.com>

* feat: cleanup extra space and import

Signed-off-by: ElHachem02 <peterelhachem02@gmail.com>

* fix: move demo to docs/examples/

Signed-off-by: ElHachem02 <peterelhachem02@gmail.com>

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Signed-off-by: ElHachem02 <peterelhachem02@gmail.com>
Co-authored-by: Michele Dolfi <dol@zurich.ibm.com>