Fix duplicate hash logic

[cgewecke]

In #854 (v0.8.7) logic was added to the collector that filters duplicate consecutive hashes because viaIR was doing that and messing up the hit counts.

However #863 reports a case where these duplicates are expected - they're inheriting onlyOwner and testing the implementation by switching the EOA e.g

 function _authorizeUpgrade(address newImplementation) internal override onlyOwner {}

The instrumentation looks like:

function a() preCondition onlyOwner postCondition {}

...so running the failure and success case one after another gives

precondition  <-- tx #1
precondtion   <-- tx #2
postcondition

PR adds logic to make sure this filtering only happens within a single transaction (frame?) using program counter tracking.