Adds shared_image_galleries resource template

[tschwarz01]

Issue-id

PR Checklist

---

• I have updated the documentation accordingly.
• I have added tests to cover my changes.
• All new and existing tests passed.
• [X ] My code follows the code style of this project.
• I ran lint checks locally prior to submission.
• [X ] Have you checked to ensure there aren't other open Pull Requests for the same update/change?

Description

Adds resource template for Azure Shared Image Galleries

Does this introduce a breaking change

• YES
• [ X ] NO

Testing

shared_image_galleries:
gallery1:
name: img-gallery
resource_group_key: consumption