Support gogs git server for oc pipeline

[csantanapr]

We are planning on using gogs git server for Cloud Native Toolkit and we need to update the IGC cli to support gogs

There are two parts.

1. Creating the git webhook programmatically into gogs server
2. Creating Tekton Trigger Artifacts to handle the payload from gogs git webhook

Gogs webhook API

https://github.com/gogs/docs-api/blob/master/Repositories/Webhooks.md#create-a-hook

Tekton Trigger changes

oc edit triggerbindings.triggers.tekton.dev template-go-gin
To update both gitrevision and gitrepositoryurl

apiVersion: triggers.tekton.dev/v1alpha1
kind: TriggerBinding
metadata:
  labels:
    app: template-go-gin
  name: template-go-gin
spec:
  params:
  - name: gitrevision
    value: $(body.after)
  - name: gitrepositoryurl
    value: $(body.repository.clone_url)

Edit Event listener

To update the header match filter: header.match('X-Gogs-Event', 'push') && body.ref == 'refs/heads/master'

apiVersion: triggers.tekton.dev/v1alpha1
kind: EventListener
metadata:
  labels:
    app: template-go-gin
  name: template-go-gin
  namespace: user1-dev
spec:
  serviceAccountName: pipeline
  triggers:
  - name: template-go-gin
    bindings:
    - kind: TriggerBinding
      name: template-go-gin
    template:
      name: template-go-gin
    interceptors:
    - cel:
        filter: header.match('X-Gogs-Event', 'push') && body.ref == 'refs/heads/master'