Add more info to output of `kit inspect`

[amisevsk]

Description

Add additional information to the output of kit inspect:

{
  "digest": "<modelkit-digest>",
  "cliVersion": "<cli-version>",
  "kitfile": {
    // Kitfile
  },
  "manifest": {
    // Manifest  
  }
}

Note this change does mean that both kit inspect and kit info produce the Kitfile for the modelkit. I've left both commands intact because kit info outputs the Kitfile in YAML format (easier to read) whereas inspect outputs JSON. We can't yet produce yaml output for inspect since the OCI manifest struct does not have yaml tags and gopkg.in/yaml.v3 does not respect json tags.

Note: to test version labelling, you will need to build kit with the version fields set:

go build -o kit -ldflags "-s -w -X kitops/pkg/cmd/version.Version=v0.0.1+test"

Linked issues

Closes #271

[amisevsk]

Applied fixes suggested above