Refine HED-Validation implementation plan

[christinerogers]

Develop multi-phase HED Validation implementation plan for optimal process, including:

• enhanced versioning of datasets with/out tags, validation and commetns
• workflow to review and follow up on / resolve comments and caveat tags
• Users can submit suggested tags, Data Author can review
• distinct Layers of tags, e.g. by one user for their own research use. ideally queryable, exportable and viewable as Layers
• Permissions to tag / validate granted via data author-controlled roles