feat: Expose customized UI links and columns

[rbreeze]

Fixes #10447

The following in workflow-controller-configmap.yaml:

data: 
  links:
    - name: Completed Workflows
      scope: workflow-list
      url: http://workflows?label=workflows.argoproj.io/completed=true
  columns: |
    - name: Workflow Completed
      type: label
      key: workflows.argoproj.io/completed

yields:

[terrytangyuan]

LGTM. The changes are pretty straightforward. Would you like to add some documentation around it? For example, how to enable this in configmap.

[rbreeze]

Sure thing! Will add docs in a separate PR

[tooptoop4]

this looks great, when will it be released?

[terrytangyuan]

It will be part of v3.5