Create a noise scalable backend.

[Duumbo]

This will be quite easy, juste modify the values in the props.JSON of the needed backend. The thing will be to chose the right error to increment. prob_meas0_prep1 and prob_meas1_prep0 will probably be the ones to be scaled, as ZNE should not be efficient on readout_error. The gate errors can also be scaled. Probably should look at how those two thing compare.