Periodically generate calls to view methods in the CallSequence

[Xenomega]

We'll want to periodically call view methods to increase coverage. Additionally, assertion testing supports config-driven options to enable assert testing of view methods, but the FuzzerWorker only produces CallSequences with calls targeting state changing methods right now, so it's never hit.

Requirements:

• Record view functions separately, but alongside the existing stateChangingMethods (see the updateStateChangingMethods method)
• Add a really low probability of sourcing a target method from it (instead of stateChangingMethods) at the top of the generateFuzzedCall method.
• Ensure the corpus.UpdateCorpusAndCoverageMaps method checks if the last call was to a view method. If it was, do not record the call sequence in the corpus at that step, as it's not a coverage-increasing sequence we'd be interested in recording, as it was not state changing.

[Jaime-Iglesias]

Will try to pick this up starting tomorrow.

Looks like this is already being worked on

[0xalpharush]

Ensure the corpus.UpdateCorpusAndCoverageMaps method checks if the last call was to a view method. If it was, do not record the call sequence in the corpus at that step, as it's not a coverage-increasing sequence we'd be interested in recording, as it was not state changing.

need clarification on this but https://github.com/crytic/medusa/pull/363 addresses the other points

[ggrieco-tob]

I think view functions should be part of the coverage, in particular if they have or can contain assertions.