Implement `odo init` example Golden Path Template

[rm3l]

As a Backstage contributor contributing a template to my organization, I want to see an example of a working end-to-end template asking users to select a Devfile and starter project, and calling odo to generate a starter project, So that I can understand how I could adapt this template to my own organization needs.

Acceptance Criteria

• [x] It should rely on the Devfile Selector Custom Field Extension (https://github.com/redhat-developer/odo/issues/7115) and odo custom actions (https://github.com/redhat-developer/odo/issues/7116)
• [x] It should provide clear documentation on how to install the template
• [x] End-to-end demo

Related Epic: https://github.com/redhat-developer/odo/issues/7114

[rm3l]

Marking this as complete. I created an example of Backstage GPT relying on the Devfile Selector custom field extension and the custom action plugin. For now, this is available as a POC under my personal GH account: https://github.com/rm3l/odo-backstage-golden-path-template/blob/main/README.md

We'll create additional issues based on the next steps about this.

Remaining things to do:

• [ ] Move this away from my personal account

/close