See #7230
This is a step towards preparing for multi-doc config.
Split the `config.Provider` interface into parts which have different
implementation:
* `config.Config` accesses the config itself, it might be implemented by
`v1alpha1.Config` for example
* `config.Container` will be a set of config documents, which implement
validation, encoding, etc.
`Version()` method dropped, as it makes little sense and it was almost
not used.
`Raw()` method renamed to `RawV1Alpha1()` to support legacy direct
access to `v1alpha1.Config`, next PR will refactor more to make it
return proper type.
There will be many more changes coming up.
Signed-off-by: Andrey Smirnov <andrey.smirnov@talos-systems.com>
Unify getting environment variables, support passing environment
variables via kernel args.
Fixes#6984
See #6999
For META this will be used to pass environment variables to the
installer for ISO images (or PXE booting).
Signed-off-by: Andrey Smirnov <andrey.smirnov@talos-systems.com>
