Loop3D/LoopStructural: improved logging, minor optimisation and bug fixes

This release includes no major changes to the functionalities of LoopStructural.

• Speed up for PLI interpolator
• Can log to file now using log_to_file(filename)
• Added tolerance parameter for pyamg solver means the solver is more stable. The default parameter is 1e-8
• Adding some pretty print functions for geological model
• Refactored the discrete supports to use a generic base support
• Interpolation support is reshaped for faults when required which should make faults more stable
• Support no longer contains the property values, this is stored on the interpolator.