Midas: support for users specified parameter directory

This merge request is a part of the work to be done for issue #84. It adds support for a user specified parameter directory to/from which the parameter files are written/read in zarr-format. The users specified parameter directories can be enabled by adding the input argument -pd #PATHTOPARAMETERDIRECTORY# to the midas command. Previously, MIdAS saved the parameter files only in temporary directories which get deleted at the end of each run. The user specified parameter directories is a first step towards making it possbile in the future to read in the parameter files for bias-adjustment run, without having to rerun calibration.