Add React Native (iOS and Android) support

[acostalima]

TODO

• Add types for react-native-fetch-api
• Integrate rn-test with aegir to run tests for both iOS and Android
• Finish CI and setup and ensure it runs to completion successfully

NOTE: React Native does not support ReadableStream for request bodies. However, just like the browser, we can use XMLHttpRequest.upload.onprogress event as a workaround.

@hugomrdias, can you give me a hand on items above? 🙏

Depends on hugomrdias/iso-url#154

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[acostalima]

Without aegir integration, tests can be run with the following commands:

$ node .aegir.js & # with the temporary changes introduced to start the echo server without aegir
$ AEGIR_RUNNER=react-native ECHO_SERVER=http://localhost:3000 npx rn-test --platform ios --simulator 'iPhone 11 (14.1)' 'test/**/*.spec.js'