Fixes https://gitlab.com/kicad/code/kicad/-/issues/15662
Fixes https://gitlab.com/kicad/code/kicad/-/issues/13587
Fixes https://gitlab.com/kicad/code/kicad/-/issues/12845
Allows placing parts from an external database that reference symbols from another loaded library. Includes: - nanodbc wrapper - database schematic library plugin - basic tests Fixes https://gitlab.com/kicad/code/kicad/-/issues/7436