[Actions] Fix init conditional run

[alexlemaire]

Issue discovered while creating a new branch release/v1.0.0 for template-kaskadi-element to test publish action and seeing init being run

The init action was defined as follow:

on:
  create:
    branches:
      - master

But the branches field is only accessible for push and pull_request webhooks (see here)

Fixed the issue by:

• removing branches field from init.yml (syntax fix)
• factored out init script into its own script file
• added conditional flow into init script to only run init when branch is master (which is actively removing ability to init again since all init files will be removed from the branch

[alexlemaire]

Fixed