CircuitResult does not apply bitflip noise

[BrunoLiegiBastonLiegi]

CircuitResult relies on the probabilities calculated from the final state after execution (QuantumState.probabilities()). When bitflip noise is present, however, the state probabilities shouldn't be used as they don't account for the bitflips in measurements. In that case, the MeasurementOutcomes.probabilities() should be used, as they should construct the probabilities starting from the samples, which account for bitflips.

from qibo import gates, Circuit
c = Circuit(1)
c.add(gates.M(0, p0=0.3))
r = c()
print(r.probabilities())
# this gives (1., 0.) instead of the expected (0.3, 0.7)

[BrunoLiegiBastonLiegi]

The fix to this bug is contained in #1076.