This extracts Docker Talos cluster provisioner as common code
which might be shared between `osctl cluster` and integration-test.
There should be almost no functional changes.
As proof of concept, abstract cluster readiness checks were implemented
based on provisioned cluster state. It implements same checks as
`basic-integration.sh` in pure Go via Talos/K8s clients.
`conditions` package was promoted from machined-internal to
`internal/pkg` as it is used to run the checks.
Signed-off-by: Andrey Smirnov <smirnov.andrey@gmail.com>
