API for device enumeration and their supported video formats

## 🚀 Feature

Provide API for enumerating camera devices and video formats the support

## Motivation & Examples

I'm working on musical app idea that needs to process video stream with lowest latency possible. In native iOS I usually want 640x480 at 120fps with highest Fov. Would great to have option to iterate all devices and their respective formats. Also utility method to choose configuration the closest to requested:

- camera position (front, back, external, unknown) and
- width, height or image aspect ratio and
- fps and
- fov

with maybe some optional flag what we want to prioritise such as PRIORITY_HIGHEST_FRAMERATE, PRIORITY_HIGHEST_RESOLUTION

Data models could be even basic for now, similar to those at OpenFrameworks:
https://openframeworks.cc///documentation/video/ofVideoDevice/
https://openframeworks.cc///documentation/video/ofVideoFormat/

The issue names no files, tests, or entry points. Begin by locating the existing camera and video-capture APIs and their platform abstractions; done means providing device and format enumeration plus a documented way to select a configuration by position, dimensions or aspect ratio, frame rate, and field of view.

Written by the indexing model from the issue text.