Support browser usage

[lance]

JavaScript is ubiquitous in the browser and the CloudEvents module should be easy to consume in that environment. A good example is the sockeye cloud event viewer. This little chunk of code would be much improved if the CloudEvent module could be used.

[github-actions]

This issue is stale because it has been open 30 days with no activity. Remove stale label or comment or this will be closed in 5 days

[lance]

I had assumed that opening a PR for this issue, and mentioning it in the PR, would remove the no-issue-activity label, but apparently not. Reopening.