Recipe to update job triggers

Create a recipe to update the types for which a job can be triggered

Examples :

Input :

name: "My job"

on:
  pull_request:
    types:
      - opened
      - edited
      - synchronize

Remove entry

on:
  pull_request:
    types:
      - opened
      - edited
-      - synchronize

Add entry:

on:
  pull_request:
    types:
      - opened
      - edited
      - synchronize
+    - closed

Add new type:

on:
+  pull_request_review:
+    types: [edited, dismissed]
  pull_request:
    types:
      - opened
      - edited
      - synchronize

As there are many possible options here, we should probably have a generic recipe that accepts a yml expression and replaces the on block with it

Start with the YAML examples in the issue and inspect existing recipes in this repository to understand how workflow changes are represented. Done means a generic recipe accepts a YAML expression, replaces the workflow's on block accordingly, and covers removing, adding, and introducing trigger types.