allow public accessors to torch state and zoom level (get and set)

[drmarkpowell]

Is your feature request related to a problem? Please describe.
For our app, we would like to run Lumina as an embedded view controller within a custom UIVC and control its torch and zoom level via our own external UI buttons or similar.

Describe the solution you'd like
In addition to the LuminaViewController internal buttons, we would like to be able to set/get the LuminaCamera torch state and current zoom level programatically.

Describe alternatives you've considered
We considered using the existing LuminaViewController buttons but we're embedding the Lumina VC in a small space and the internal buttons are occluding the camera view too much (we are scanning barcodes with it).

Additional context
We are using Lumina for this app mainly to scan barcodes, within a custom UIViewController that presents a few other custom controls for related things.

Would making the LuminaCamera public be appropriate, or would adding additional set/get method to LuminaViewController be more acceptable? I'd be happy to fire a PR your way.

[dokun1]

Hey! Thank you so much for this issue and tagging this.

I think the most appropriate way forward would be to add setters and getters for those levels. I think LuminaCamera is and should be private to prevent misuse of the interface. I have seen other use cases similar to this with the simple presence of other buttons on the UI, thanks to @gerriet and his contribution.

Let me know if you agree with this - happy to review a PR of it!