Add simulation-based integration test for the efficacy of error mitigation techniques

[TsafrirA]

What is the expected enhancement?
We want to add simulation-based test that will verify the efficacy of various error mitigation techniques. We want to demonstrate that given a noisy simulation, the estimate improves as the error mitigation is applied. Tests should cover different observables and parameters, and cover the following cases:

• Resilience levels (vanilla, TREX, ZNE with gate folding) Test the impact of resilience levels for Executor-based Estimator (Local mode simulation) #3174
• PEC
• PEA

Acceptance criteria
Tests are added.