feat: extend multiple templates validation to trestle author folders

[AleJo2995]

Types of changes

• Hot fix (emergency fix and release)
• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Documentation (change which affects the documentation site)
• Breaking change (fix or feature that would cause existing functionality to change)
• Release (develop -> main)

Quality assurance (all should be covered).

• My code follows the code style of this project.
• Documentation for my change is up to date?
• My PR meets testing requirements.
• All new and existing tests passed.
• All commits are signed-off.

Summary

Closes #1424

Key links:

• Sonar coverage

Before you merge

• Ensure it is a 'squash commit' if not a release.
• Ensure CI is currently passing
• Check sonar. If you are working for a fork a maintainer will reach out, if required.

[AleJo2995]

@jayhawk87 here's the PR with the changes regarding #1424 . Please take a look and feel free to review it as wish and provide any feedback on it prior release :)

[AleJo2995]

@vikas-agarwal76 I have addressed your comments correspondingly. Can you please review again?

[vikas-agarwal76]

LGTM

[AleJo2995]

@vikas-agarwal76 I have explore the options and now I understand. x-trestle-ignore is actually a field in the template that the user will explicitly define which fields in the instance don't need to be validated. In that way, we can set x-trestl-template-type field in the instance without having the mismatch. Look at the latest changes, review so I can proceed to merge :)