fix(cli): handle multi-resource yaml in offline lint. Fixes #12137

[wang-wayne]

Fixes #12137
Fixes #10608

Motivation

If there are multiple templates in one yaml file. The argo lint --offline can only get the first template.
Because the yaml.Unmarshal function is used to parse a single YAML document.

Modifications

Read yaml file with common.ParseObjects in offline mode.

Verification

e2e test.
argo lint --offline test.yaml

apiVersion: argoproj.io/v1alpha1
kind: WorkflowTemplate
metadata:
  name: hello-world-template-local-arg-1
spec:
  templates:
    - name: hello-world
      inputs:
        parameters:
          - name: msg
            value: "hello world"
      container:
        image: docker/whalesay
        command: [cowsay]
        args: ["{{inputs.parameters.msg}}"]
---
apiVersion: argoproj.io/v1alpha1
kind: WorkflowTemplate
metadata:
  name: hello-world-template-local-arg-2
spec:
  templates:
    - name: hello-world
      inputs:
        parameters:
          - name: msg
            value: "hello world"
      container:
        image: docker/whalesay
        command: [cowsay]
        args: ["{{inputs.parameters.msg}}"]
---
apiVersion: argoproj.io/v1alpha1
kind: Workflow
metadata:
  generateName: hello-world-local-arg-
spec:
  entrypoint: whalesay
  templates:
    - name: whalesay
      steps:
        - - name: hello-world
            templateRef:
              name: hello-world-template-local-arg-2
              template: hello-world

Add unittest case.

[agilgur5]

@miltalex do you want to try reviewing this? Since you've worked on argo lint before

[agilgur5]

I'm curious if this also fixes #10608?

[miltalex]

@miltalex do you want to try reviewing this? Since you've worked on argo lint before

I would be happy to review it

[wang-wayne]

I'm curious if this also fixes #10608?

@agilgur5 Yes, I had a validation. This PR also fixes #10608.

[wang-wayne]

@miltalex do you want to try reviewing this? Since you've worked on argo lint before

I would be happy to review it

Hi @miltalex , thank you for reviewing my PR! Do you have any comments or suggestions to share? I would appreciate any feedback you might have. Thank you!

[miltalex]

Nice work, thank you very much for submitting the fix. I have a small stylistic suggestion otherwise LGTM

[miltalex]

/retest