Training: create or update trainer in training role

[wgj]

Create or update the role for trainers in training.
Trainers in Training (TiTs) Should have the same abilities as trainers. They are a subtype of trainers, used as tracking by TA.

A TiT can:

• change attributes of a training object where they are listed as a trainer
• flag Students of a training object where they are listed as a trainer, and the student is listed as a student