Adding the osv-gui is a submodule of the httpserver

This adds the OSV-GUI repository as a submodule of the httpserver

Reviewed-by: Tomasz Grabiec <tgrabiec@gmail.com>
Signed-off-by: Amnon Heiman <amnon@cloudius-systems.com>
Signed-off-by: Pekka Enberg <penberg@cloudius-systems.com>
Http Server: Compile and copy the gui to the image

The httpserver compilation needs to verify that the gui submodule was
pulled, compile and add it as part of the image.

Signed-off-by: Amnon Heiman <amnon@cloudius-systems.com>
Signed-off-by: Pekka Enberg <penberg@cloudius-systems.com>
Httpserver: Mapping the GUI files in the server

This adds a mapping of the GUI to the server, after this patch a call to
http://192.168.122.89:8000/dashboard/
Will display the GUI.

Reviewed-by: Tomasz Grabiec <tgrabiec@gmail.com>
Signed-off-by: Amnon Heiman <amnon@cloudius-systems.com>
Signed-off-by: Pekka Enberg <penberg@cloudius-systems.com>