Issue 11638 - Adding drag and drop feature

Implement drag and drop feature in Kicad:

• dropping files to Kicad manager :
  • *.kicad_pro, *.pro -> open project;
  • gerber and job files -> open in Gerbview editor;
  • Eagle and Cadstar files -> open project.
• dropping file to schematic editor -> append schematic;
• dropping library file to Symbol editor -> add library;
• dropping board file to PCB editor -> append board;
• dropping library or footprint file to Footprint editor -> add library or import footprint;
• dropping ZIP file or gerber files to Gerbview editor -> open files;
• dropping sheet file to Drawing Sheet editor -> open sheet.

See issue #11638 (closed)