[Streaming] bf-streaming 4.7.0 requires TS projects to use "dom" lib in tsconfig.json

[stevengum]

Versions

What package version of the SDK are you using. 4.7.0

Describe the bug

BrowserWebSocket includes a dependency on a Browser type (WebSocket) which is satisfied through our package including "dom" in our tsconfig.json for bf-streaming.

botbuilder-js/libraries/botframework-streaming/src/webSocket/browserWebSocket.ts

Lines 10 to 11 in a0db677

	export class BrowserWebSocket implements ISocket {
	private webSocket: WebSocket;

botbuilder-js/libraries/botframework-streaming/tsconfig.json

Line 4 in 688c9bf

"lib": ["es2015", "dom"],

Projects that use botbuilder and do not have "dom" in the libs of their tsconfig.json will be unable to build due to the missing type.

The immediate workaround is for projects with a dependency on botframework-streaming or botbuilder to add "dom" to the project's tsconfig.json, but we should remove this from our package and replace any "dom"-specific types with interfaces.

Expected behavior

Ability to build TS libraries that have a dependency on botbuilder without changing their tsconfig.json

Additional context

First reported via howdyai/botkit#1894

[bug]