update stable diffusion script and doc (#15846)
### Description
Update script:
(1) change some float16 verbose logging to debug level.
(2) Let requirements-cuda.txt includes requirements.txt
(3) Use an environment variable ORT_DISABLE_TRT_FLASH_ATTENTION=1 to
avoid black image in 2.1 model. Update benchmark and doc.
(4) Update document to include command lines to build ORT rocm from
source.
(5) Update optimize_pipeline.py so that user can disable packed qkv/kv
from command line options.
(6) Update document to use torch < 2.0 for onnx export.
### Motivation and Context
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