Display evaluation time and iterations after authorization

[divarvel]

This makes it easy to see how much time evaluation took.

For biscuit inspect

✅ Public key check succeeded 🔑
❌ Authorizer check failed 🛡️ (139μs, 0 iterations)
No policy matched

For biscuit inspect-snasphot

⏱️ Execution time: 120μs (1 iterations)
✅ Authorizer check succeeded 🛡️ (148μs, 1 iterations)
Matched allow policy: allow if user($u)