Create Fault Class for Modeller's Toolkit (v2 workflow)

The second workflow to be implemented in the Modeller's Toolkit is intended to process the input data for a fault and/or set of fault sections (e.g. geometry, slip, tectonic region parameters etc.), apply calculations to determine the activity rate and magnitude frequency distribution and export the model into the nrml simple, complex or generalised fault typology. In addition to the creation of the basic calculators (geometry, activity rate etc.), the fault class needs to accommodate the specification and modelling of uncertainties in the input parameters (e.g. slip rate, area etc.) in a flexible manner.