Updated Inductor_SMD generator to support polarity markers

This MR heavily reworks the inductor SMD generator.

Most notable changes are:

• Split the layer generation onto static methods
• Added polarity marker (The yaml file now supports a has_orientation: true) flag
• Added generated with kicad-footprint-generator line to all generated models. This change required regenerating all models.
• Ran Python black against the modified code (https://github.com/psf/black)

This MR depends on !1148 (merged)

These changes are required for the upcoming MR to add the Coilcraft MSS series as these inductors should have a pin 1 marker.