Feature Request: Integrate ATT&CK Navigator Layers

[dfirence]

@nshalabi - Excellent work and design of a useful utility with SQLITE

Requesting you add a feature to integrate a layer from the ATT&CK Navigator onto the tool you have - AttackView.exe

As your user, I want to grab a layer from MITRE or other people, import the JSON as a new plan and work from there.

Example: APT29 Evaluation

I want the layer's highleghted in Green to render in my plan within the AttackView.exe application

[nshalabi]

Thank you for your feedback, added to the list of requested features.