Metrics: measure onchain profit for protocols

[ccerv1]

Describe the feature you'd like to request

For protocols that have a protocol fee, measure the amount of protocol fees collected.

Describe the solution you'd like

Ideally there would be an event that captures the protocol revenue associated with every onchain interaction, similar to how we capture invocations and L1/L2 gas fees

Describe alternatives you've considered

n/a