Programatic download/export for workflow history

[Assem-Hafez]

Fixing issue of export button not downloading history for correct origin.
The problem was that the export button is using the current origin to request the information while it should be using the origin related to the domain itself.
In order to fix that, the href was replaced with an onclick handler which fetches the history and create a blob url that can be used for downloading (note: using httpService for fetching handles the origin automatically).

Another changes:

• Install chai-spies to be used in test cases
• mock api response for xxx\export api and provide it using withExportHistory
• update unit tests