Add GenericObject plugin files and assets

- Introduced default icon images in PNG and SVG formats.
- Added example icons for car and cube in SVG format.
- Created setup file for the GenericObject plugin with versioning and directory definitions.
- Included a header file with licensing information for the plugin.
- Added a remove.txt file with instructions for safe deletion.

plugins/genericobject/AUTHORS.txt

@@ -0,0 +1,9 @@
+Plugin Genericobject developers :
+
+Walid Nouh, Teclib'
+Alexandre Delaunay, Teclib' 
+
+Occasional contributors :
+François Legastelois, Teclib'
+Jean-Max Reymond, CSK Solutions
+Xavier Caillaud, Infotel