Move prover struct to coordinator group

[mfcastellani]

What does this PR does?

Improve project organization moving the prover struct

How to test?

make test

Checklist

These are the criteria that every PR should meet, please check them off as you review them:

• [ ] Include tests
• [ ] Respect code style and lint
• [ ] Update swagger file (if needed)
• [ ] Update documentation (*.md) (if needed)