Add support for capture="environment"

[e-knaake-covadis]

I have a usecase where I want to use this library for image compression and my code is already structured around this library. Though now I have a requirement to open the camera from a PWA to upload a new file. HTML is starting to support capture="environment" for this.

Looking at the methods generateUploadInputRenderer and generateUploadInputNative where they both use a flag mutliple to add extra attributes I think it might be as easy as adding another flag for this.

Perhaps it is even possible to take an arbritary list of attributes to add to the input?

Could this library support this feature?