On authorization of image builder on azure, the user will be redirected
to portal.azure.com. The response mode is changed to query instead of
form_post because form_post makes a POST request while query makes a GET
request. portal.azure.com does not respond when we make a POST request
to it so users will not be redirected unless we use the response mode
of query.
The info text is updated and the authorize button is moved below tenant
ID. The tenant ID is now validated as a valid GUID and if is not valid
the authorize button is disabled. This tenant id is now used to validate
image builder on azure because the authorize url containing the tenant
id will authorize for any microsoft account type. Tests are also
updated.
