Add COTO-3600 series low EMF relays

Symbol MR: kicad-symbols!4001 (merged)

3D model MRs: kicad-packages3D!910, kicad-packages3D-source!379

Datasheet: https://cotorelay.com/wp-content/uploads/2014/09/3600_series_reed_relay_datasheet.pdf
Note: Datasheet doesn't make it clear but unconnected pins in the pinout diagrams are not fitted.

Screenshots:

3602

3650

3660

Courtyard detail

Y courtyard is rounded up to fit 0.01mm grid.