fix: copy input parameter defaults to output in suspend templates

[Joibel]

Fixes argoproj#12896

Motivation

This workflow apparently worked in 3.4, I haven't tried to work out why.

apiVersion: argoproj.io/v1alpha1
kind: Workflow
metadata:
  name: suspend-with-input-defaults
spec:
  entrypoint: main
  templates:
  - name: main
    steps:
    - - name: wait
        template: wait
  - name: wait
    suspend:
      duration: "0s"
    inputs:
      parameters:
        - name: input
          default: "Hello World"
        - name: select
          default: default
          enum:
            - default
            - option1
            - option2
    outputs:
      parameters:
        - name: input
          valueFrom:
            supplied: {}
        - name: select
          valueFrom:
            supplied: {}

Modifications

We now observe the default values of the inputs if the output doesn't have defaults, for suspend templates only

Verification

New unit test, which verified the workflow passes and checks the values.
The workflow would formerly failed.

Documentation

None required, bug fix