Converts iOS implementation from Objective-c to Swift
# During the conversion process some updates to the code structure were also made
- Modularize codebase from single file to smaller focused files
- Untangled large nested IF statements
- Added more null checks, since Swift is more strict with null pointers
- Added property to allow for decoding of local video sources with self contained key for offline playback
- Updates example apps to test react-native 0.63.4 and uses auto native dependency imports for android and ios
Various updates for React Native Windows
**Docs**
* Fixed windows installation in readme
* Added local dev setup instructions
**Build**
* Added VS solutions for RNW 0.61, 0.62, and 0.63+
* Added clang-formatting definition
**Features**
* Fixed autolinking for RNW 0.63+
* Added support for `rate` property
**Examples**
* Upgraded examples/basic to RN 0.61 and replaced broken windows app
