Issue with dcsource in netlist for interconnect

[tmcnitt]

I am using klayout 0.26.9, Lumerical 2020 R2.4, and SiEPIC 0.36.8. When I go to export a layout built with the AIM Active PDK, I receive an error that lumerical does not have the element 'dcsource'. I believe this comes from here. However, when I manually export the netlist and change every occurrence to '"DC Source"' in the netlist, Lumerical imports everything correctly. I would assume this has something to do with the more recent version of Lumerical. Depending on how you feel about backwards combability, I could create a simple PR to change that naming scheme.