Introduce a new `admission` subpackage to factor out the responsability
to create `PodAdmitResult` objects. This enables resource manager
to report specific errors in Allocate() and to bubble up them
in the relevant fields of the `PodAdmitResult`.
To demonstrate the approach we refactor TopologyAffinityError as a
proper error.
Co-authored-by: Kevin Klues <kklues@nvidia.com>
Co-authored-by: Swati Sehgal <swsehgal@redhat.com>
Signed-off-by: Francesco Romani <fromani@redhat.com>