OctoPrint camera streamer implementation

[T-Robertson]

🌟 Briefly describe the feature

Add camera to Octoprint LXC to stream attached webcam for printing

📝 Detailed description

For Octoprint to run an attached webcam, mjpg-streamer could be added to the LXC installation to help ease of use. Its suggested that the camera streaming runs externally to the Octoprint system.

💡 Why is this useful?

To give the user the option of using a USB camera to view printing. You can manually add the streamer, but adding it at the installation of the LXC is for ease of use, and doesn't need further input for setup

[MickLesk]

Not in Script himself. Maybe anyone write an guide.

We only serve the default scripts, not any massive (and in this case very old) addons