NodeJS - Outside of browser environment

Issue #, if available:

https://github.com/awslabs/amazon-kinesis-video-streams-webrtc-sdk-js/issues/115

Description of changes:

Allow for compatibility when using this package outside of the browser environment.
WebSocket and atob()/btoa() are natively supported in the browser environment. Previously, if run outside of browser environment, some SignalingClient methods wouldn't work, as those globals don't exist. Now, if the browser environment is not detected, then we try the nodejs equivalent of those methods.
Remove .toJSON(), it is not necessary.
New dependency: ws, as fallback.
- Note: Buffer comes with NodeJS (global object). https://nodejs.org/api/buffer.html
- Before: kvs-webrtc-min.js = 22.8 KiB; After: 23.2 KiB

Testing

Add new unit tests, they pass.
Existing unit tests still pass.
Test page is still working via npm run develop (connected master+viewer to verify).
- C
- Android
- iOS
Exported and imported the project in a new nodejs project. Files below:

package.json

``` { "name": "js-sdk-test", "version": "1.0.0", "description": "", "main": "index.js", "scripts": { "test": "echo \"Error: no test specified\" && exit 1" }, "author": "", "license": "ISC", "dependencies": { "amazon-kinesis-video-streams-webrtc": "^2.1.0" } } ```

index.js (some information redacted)

``` const SignalingClient = require('amazon-kinesis-video-streams-webrtc').SignalingClient; const Roles = require('amazon-kinesis-video-streams-webrtc').Role; try { let client = new SignalingClient({ channelARN: "arn:aws:kinesisvideo:us-west-2:x:channel/demo-channel/x", channelEndpoint: "wss://m-x.kinesisvideo.us-west-2.amazonaws.com", role: Roles.MASTER, region: 'us-west-2', credentials: { accessKeyId: "x", secretAccessKey: "x", sessionToken: "x", }, }); client.open(); console.log('FINISHED!') } catch (e) { console.error(e); } ```

And verified the new one worked by replacing the node_modules/amazon-kinesis-video-streams-webrtc/lib folder with the new one.

Before:

/Users/me/Downloads/js-sdk-test/node_modules/amazon-kinesis-video-streams-webrtc/lib/SignalingClient.js:108
                        this.websocket = new WebSocket(signedURL);
                                             ^

ReferenceError: WebSocket is not defined
    at SignalingClient.<anonymous> (/Users/me/Downloads/js-sdk-test/node_modules/amazon-kinesis-video-streams-webrtc/lib/SignalingClient.js:108:46)
    at step (/Users/me/Downloads/js-sdk-test/node_modules/tslib/tslib.js:141:27)
    at Object.next (/Users/me/Downloads/js-sdk-test/node_modules/tslib/tslib.js:122:57)
    at fulfilled (/Users/me/Downloads/js-sdk-test/node_modules/tslib/tslib.js:112:62)
    at process.processTicksAndRejections (node:internal/process/task_queues:95:5)
Emitted 'error' event on SignalingClient instance at:
    at SignalingClient.onError (/Users/me/Downloads/js-sdk-test/node_modules/amazon-kinesis-video-streams-webrtc/lib/SignalingClient.js:282:14)
    at /Users/me/Downloads/js-sdk-test/node_modules/amazon-kinesis-video-streams-webrtc/lib/SignalingClient.js:84:50
    at process.processTicksAndRejections (node:internal/process/task_queues:95:5)

After:

FINISHED!

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awslabs / amazon-kinesis-video-streams-webrtc-sdk-js