Detect and handle duplicated keyboard device names

[mschout]

IF a keyboard name is duplicated in the device list, append the device number to the end.

I have no idea if there is a better way to do this or not, and I have very little rust experience, but this gets my Rainy 75 working as it exposes itself on two devices with the exact same name and the lower numbered device is always the one that receives the events.

fixes #49

[RichardFevrier]

Isn't already handled by #41 ?

[mschout]

Isn't already handled by #41 ?

Yeah, looks similar. Can close this in favor of #41 I did comment over there that maybe should make sure the numbering is deterministic (probably by sorting the devices), but otherwise its basically the same solution.