feat(forge): invariant tests instrumentation with function call summaries

[PaulRBerg]

Component

Forge

Describe the feature you would like

It would be useful to get a report of the distribution of function calls at the end of a successful invariant test run.

Users currently have to resort to manually instrumenting the function calls by adding storage vars, which clutters the handler contracts with logic that is unrelated to the actual business logic of the protocol. See, for example, the numCalls mapping defined in Lucas' invariant-examples repo, and also his invariant_call_summary function.

This is something that should be done by Forge, which is in charge of orchestrating the invariant tests anyway.

[PaulRBerg]

If you like this idea, @mds1, should we add it to your todo list in #3412?

[mds1]

Duplicate of #3607? (which is already tracked in #3412)

[PaulRBerg]

I missed that issue! Sorry, closing.