Convert plugins to use PHP Attributes only.

📌 Increase minimum requierments for 2.x branch Active would need to occur first.

Proposed patch is a complete removal of Annotations. As noted in the IS the 8.x-1.x branch is not compatible with the 2.x, in regards to plugin definitions as such there is no BC reason to maintain Annotations in the 2.x branch.

Proposed patch is essentially a direct copy of the Annotations with slightly stricter typedef requirements.

Ready for review..

I have questions about should we keep all of the older TFA Annotation fields (like helpLinks) which we may wish to consider removing before this becomes API spec however we have until Beta1 to reconsider that.

Automatically closed - issue fixed for 2 weeks with no activity.