Added parameter for device throughput limit

[cedricpradalier]

Hello, I was testing this package with multiple cameras on a gigabit switch and I could not get more than one camera streaming on the bus (Blackfly camera) without explicitly setting the device throughput limit. I had the same problem using the spinnaker app, so I validated it there before adding the parameters to the ros application.

I can now stream 4x6MP cameras in color at 5Hz, using a 30'000'000 throughput limit for each camera (reaching close to the 125'000'000) theoretical limit of the bus.

[cedricpradalier]

Note: this update may be redundant with the other pull request in the queue from RomainV92. If the other one is accepted, there is probably no need to accept this one.