fix: Add version property to http-event-schema

[adebayor123]

Problem:

• When the web client creates an HTTP event that contains an error, it relies on errorEventToJsErrorEvent that creates a JsErrorEvent to populate the error field in the http-event. JsErrorEvent by default adds version, which does not exist in the webclient's and dataplane's http-event schema.
• This was not caught on the web client as the FetchPlugin and XhrPlugin are unaware of the property details within the error object created by errorEventToJsErrorEvent.
• As a result, any HTTP events that contains an error was rejected by the dataplane due to this event schema discrepancy.

Fix:

• Dataplane event schema changes have been merged in.
• This PR updates the http-event schema to eliminate the schema difference between dataplane and web client and edits existing unit tests to check for the version property in FetchPlugin.test and XhrPlugin.test.

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