[Custom templates] [Feature Enhancement] Workflow images: Optimize how users add workflow images to templates

### Description:
Feature enhancement to provide seamless experience for adding workflows to custom templates. Possible solutions include leveraging Copilot, etc.

### Current experience:
1. Users are in Logic Apps Templates
2. They have to navigate to the existing workflow:
- take a screenshot of the workflow in light mode
- switch to dark mode, take another screenshot
- open Azure Blob Storage
- upload the screenshots to their Azure Blob Storage
3. Navigate back to the template experience
4. Add the link to the field