fix Clb_converged, don't remove 'b' from folder names

[orichters]

• since a while, calibrations show no Clb_converged anymore, but just converged. This misleads AMT runs into thinking some run did not converge
• Did we have input_02.gdx etc. until ~ September 2022? The amount of input_xx.gdx files was used to determine whether a converged iteration was a successful calibration. Now, look for the corresponding fulldata_xx.gdx which did not seem to exist earlier.
• fix a small bug if you manually pass a folder that contains a b (with rs2 SSP2-base`), that was sometimes removed.