Also adds new parameters to AM sources for ngspice-43.
Also fixes a bug in the spice parameter parser (which would
puke on any parameter name starting with one of the flag
parameter strings).
Also fixes a bug where the skipped source parameters would
get set to "0" instead of their default values.
Fixes https://gitlab.com/kicad/code/kicad/-/issues/16393
Also fixes a bug where all VDMOS instance parameters weren't marked as
instance parameters.
Also fixes a bug where VDMOS thermal models weren't supported (they
have two extra pins: Tj and Tcase).