Add a halt-on-failure configuration parameter, allow fuzzing to continue to discover multiple results

[Xenomega]

Currently the project will halt when the first failed test is discovered. Instead, we should have this as a configurable option where by default, we continue fuzzing to find other violations, but a user can specify to halt-on-failure if they choose.

This will require the following changes:

• Adding a configuration parameter that enables halt-on-failure.
• Refactoring of fuzzerWorker.testTxSequence to continue testing the sequence for other failures rather than stopping on the first failure.
• Refactoring fuzzerWorker.run to not halt when a unique test is reported for the first time.
• Refactoring the test results structures a bit
• Removing property tests to validate as we find ways to violate them (to avoid re-testing them).
• Adding logic to halt when there's nothing left to test.

This should be done with or after #21 , as that will change the results structure.