Enhancements to WebcamVideoStream (VideoCapture Properties and Release)

[karjanme]

Address a few limitations with WebcamVideoStream:

1.) Set resolution of the VideoCapture, or use a capture object with custom properties already set.
Based on feedback provided in #68 , the constructor has been improved to allow optional args for a VideoCapture object and a resolution tuple.
#68 (comment)

2.) Address #35 by releasing the VideoCapture when the WebcamVideoStream is stopped.

Thank you for the time you've already spent developing this awesome library.

[karjanme]

@jrosebr1 Please consider this PR when you have time. Let me know if you have any feedback on it. Thank you!

[makew0rld]

Not the maintainer, but thanks for this! I would suggest default setting the resolution to something like (10000, 10000), as this will force OpenCV to use the highest possible resolution of the camera, which it doesn't do by default.

[karjanme]

Not the maintainer, but thanks for this! I would suggest default setting the resolution to something like (10000, 10000), as this will force OpenCV to use the highest possible resolution of the camera, which it doesn't do by default.

@makeworld-the-better-one I like your idea, but I'll leave it up to the maintainer to decide how they want this to work. I defaulted the resolution here to (320, 240) because that is the default in the other existing classes VideoStream and PiVideoStream.

[makew0rld]

Thanks for the changes!

[karjanme]

@ariG23498 please consider this PR to fix a couple issues that are frequently reported by other users.