feat: Support audio input (#1763)

* scaffolding in place

Signed-off-by: Peter Staar <taa@zurich.ibm.com>

* doing scaffolding for audio pipeline

Signed-off-by: Peter Staar <taa@zurich.ibm.com>

* WIP: got first transcription working

Signed-off-by: Peter Staar <taa@zurich.ibm.com>

* all working, time to start cleaning up

Signed-off-by: Peter Staar <taa@zurich.ibm.com>

* first working ASR pipeline

Signed-off-by: Peter Staar <taa@zurich.ibm.com>

* added openai-whisper as a first transcription model

Signed-off-by: Peter Staar <taa@zurich.ibm.com>

* updating with asr_options

Signed-off-by: Peter Staar <taa@zurich.ibm.com>

* finalised the first working ASR pipeline with Whisper

Signed-off-by: Peter Staar <taa@zurich.ibm.com>

* use whisper from the latest git commit

Signed-off-by: Michele Dolfi <dol@zurich.ibm.com>

* Update docling/datamodel/pipeline_options.py

Co-authored-by: Michele Dolfi <97102151+dolfim-ibm@users.noreply.github.com>
Signed-off-by: Peter W. J. Staar <91719829+PeterStaar-IBM@users.noreply.github.com>

* Update docling/datamodel/pipeline_options.py

Co-authored-by: Michele Dolfi <97102151+dolfim-ibm@users.noreply.github.com>
Signed-off-by: Peter W. J. Staar <91719829+PeterStaar-IBM@users.noreply.github.com>

* updated comment

Signed-off-by: Peter Staar <taa@zurich.ibm.com>

* AudioBackend -> DummyBackend

Signed-off-by: Christoph Auer <cau@zurich.ibm.com>

* file rename

Signed-off-by: Christoph Auer <cau@zurich.ibm.com>

* Rename to NoOpBackend, add test for ASR pipeline

Signed-off-by: Christoph Auer <cau@zurich.ibm.com>

* Support every format in NoOpBackend

Signed-off-by: Christoph Auer <cau@zurich.ibm.com>

* Add missing audio file and test

Signed-off-by: Christoph Auer <cau@zurich.ibm.com>

* Install ffmpeg system dependency for ASR test

Signed-off-by: Christoph Auer <cau@zurich.ibm.com>

---------

Signed-off-by: Peter Staar <taa@zurich.ibm.com>
Signed-off-by: Michele Dolfi <dol@zurich.ibm.com>
Signed-off-by: Peter W. J. Staar <91719829+PeterStaar-IBM@users.noreply.github.com>
Signed-off-by: Christoph Auer <cau@zurich.ibm.com>
Co-authored-by: Michele Dolfi <dol@zurich.ibm.com>
Co-authored-by: Michele Dolfi <97102151+dolfim-ibm@users.noreply.github.com>
Co-authored-by: Christoph Auer <cau@zurich.ibm.com>