Add initial Dockerfile for distributed training targets (#4578)
* add training dockerfile tested for examples repo
* forgot pytorch patch for build from source
* make apt-get update -y adjacent apt-get install -y due to Docker caching rules
* comment for mellanox libraries
* mpi4py comment as I forgot where it came from
* apparently curl not included anymore
* grr.. nvidia change nccl location
* dont need findnccl.patch after nvidia changed nccl location
* pr comment /opt/ompi4 => /opt/openmpi-xxx
* switch to pip install pytorch
* use Release instead of RelWithDebInfo
* comment wording
* wordin
* missed RelWithDebInfo => Release
* replace Mellanox with libibverbs
* stale comment
* ordering
* no more ninja
* add / at end of copy
* update cgmanifest.json
* pr comments
Co-authored-by: suffian khan <sukha@OrtTrainingDev1.af05slrtruoetgaxwwjv5nsq5e.px.internal.cloudapp.net>