Use botframework-streaming browser dist; misc. refactoring and linting

[stevengum]

Specific Changes

• Move generated types out of directLine.ts to types.ts
  • Alphabetically sorts the types and their properties
• Change from import * as BFSE from 'botframework-streaming' to import { ... } from 'botframework-streaming/browser/index-browser'
• Update CHANGELOG.md with corresponding changes

Testing

The change in directLineStreaming.ts to point to 'botframework-streaming/browser/index-browser' has been validated with unit tests and tested E2E with botframework-webchat@4.10.0 via the following matrix:

	botframework-streaming@4.9.2	botframework-streaming via microsoft/botbuilder-js#2753
HTTP	✅	✅
Websockets via DL-ASE	✅	✅

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This also serves as the starting point for addressing issue #288.

[stevengum]

Closing in favor of #306