feat: Add License Check Workflow to each Template

[tomarra]

Description

Looking to add in the license check workflow for our templates https://workflows.vgv.dev/docs/workflows/license_check

Requirements

• Each template has the license check workflow included
• The workflow its own file/workflow overall
• The workflow is triggered for every PR and merge to main
• The default set of licenses allowed are 'MIT,BSD-3-Clause,BSD-2-Clause,Apache-2.0'

[JohnWeidner]

License check is not working on Flutter projects. (see issue 297 After the PR for that is merged, I'll create my PR for this one.

[erickzanardo]

@JohnWeidner Are you still working on this one?