Add generic, configurable modular RCD functionality (MRCD)

Modular RCDs can have adjustable time delay and adjustable tripping current as well as coming in a variety of current capacity ratings that are not present in ProDesign.

At the moment only Instantaneous and Selective RCDs up to 100A are generally available in ProDesign outside of the Schneider Vigi range which cannot be adjusted.

Configuring cascading RCD characteristics at multiple levels of switchgear is currently not possible outside of MCCBs with adjustable LSIG pickups.