Allow user to pass in VID/PID to find_and_init_boot_mouse()

[FoamyGuy]

This would make it so code using this library could specify a device they are hoping to find.

That would make possible to have a combo keyboard/mouse, and a regular mouse both connected and to specify that the regular mouse should be the one used by this library where-as the combo device will get left alone to act as keyboard. Right now I believe this is just a 50/50 chance to work "correctly" based on the order of devices returned by core USB API.

[FoamyGuy]

Maybe this is unnecessary if the order of the devices consistently follows port 1 then port 2. I've been using a mouse in port 1 and a combo device in port 2 and it seems to always correctly find the mouse leaving the keyboard for the CPy core.