Add 'platform' option when pulling in docker_image

[ondrejmo]

SUMMARY

It would be handy it was possible to specify platform when pulling an image. Currently when pulling multiarch image that doesn't have a special tag for each architecture it automatically starts pulling the image with architecture of userspace and there's no way to override this behaviour other than using cli:

- command:  docker pull --platform=linux/arm64 minio/minio:RELEASE.2021-01-16T02-19-44Z

• i.e. when on Raspbian with aarch64 kernel and armv7 userspace, it pulls armv7 image and fails if it doesn't exist, manual override using --platform arm64 is needed to fix it, but docker_image doesn't support platform option when pulling

ISSUE TYPE

• Feature Idea

COMPONENT NAME

docker_image

ADDITIONAL INFORMATION

• Related issue: Add 'platform' option to build options in docker_image #22

[felixfontein]

Should be easy to implement, as pull does support it: https://docker-py.readthedocs.io/en/stable/api.html#docker.api.image.ImageApiMixin.pull

[felixfontein]

resolved_by_pr #89