Browser Fixes

Includes a number of fixes for the browser shim

• Update http sample to use new http interface
• Webpack error in http module
• Corked event args not unpacking properly leading to undefined arguments
• mqtt connect timeout default should be a reasonable value in milliseconds, not seconds
• activate http streams in browser http sample
• rework HttpClientConnection constructor to not be confusing and erroneously ambiguous with null/undefined parameters
• audit fix for vulnerable dependencies