Support for Docker manifests base images add-on build

[frenck]

Proposed change

Since we support manifests now for add-on images, this PR set in motion to use a single base image for all architectures using a manifest, by allowing build_from to be a string (instead of mapping for each architecture).

So instead of doing this:

# build.yaml
build_from:
  aarch64: ghcr.io/hassio-addons/base:12.2.0
  amd64: ghcr.io/hassio-addons/base:12.2.0
  armhf: ghcr.io/hassio-addons/base:12.2.0
  armv7: ghcr.io/hassio-addons/base:12.2.0
  i386: ghcr.io/hassio-addons/base:12.2.0

This PR will also allow for this:

# build.yaml
build_from: ghcr.io/hassio-addons/base:12.2.0

Needs:

• [ ] Documentation adjustments
• [ ] Support for the builder to handle this
• [ ] Adjustment to add-on linter GitHub Action

Type of change

• [ ] Dependency upgrade
• [ ] Bugfix (non-breaking change which fixes an issue)
• [ ] New feature (which adds functionality to the supervisor)
• [ ] Breaking change (fix/feature causing existing functionality to break)
• [ ] Code quality improvements to existing code or addition of tests

Additional information

• This PR fixes or closes issue: fixes #
• This PR is related to issue:
• Link to documentation pull request:
• Link to cli pull request:

Checklist

• [ ] The code change is tested and works locally.
• [ ] Local tests pass. Your PR cannot be merged unless tests pass
• [ ] There is no commented out code in this PR.
• [ ] I have followed the development checklist
• [ ] The code has been formatted using Black (black --fast supervisor tests)
• [ ] Tests have been added to verify that the new code works.

If API endpoints of add-on configuration are added/changed:

• [ ] Documentation added/updated for developers.home-assistant.io

[frenck]

on get_docker_args we should set the right platform as we do on docker pull

~~It does already? Or am missing something?~~ Oh we don't...

[pvizeli]

If we do that, we can merge the PR

[mdegat01]

@frenck @pvizeli FYI I rebased this, added the platform to get_docker_args and added a couple tests so I think this is ready now if you both want to take a look.

[frenck]

Oh shit totally forgot about this one 🙈 Thanks, @mdegat01 ❤️

[frenck]

Looks good to me, however, I cannot approve as the PR author