fix(test): Fix the failing OAuth functional tests. (#4630) r=@vbudhram
fix(test): Fix the failing OAuth functional tests. (#4630) r=@vbudhram

* fix(test): Fix the failing OAuth functional tests.

The functional tests specified extra query parameters. The query parameter
processing in `openFxaFromRp` only appended the query parameters if more
than 1 query parameter was specified. DOH

fixes #4612

* fix(test): Fix the logic re-opening force_auth w/ query params.

There was a small error in the logic for when to re-open the force_auth
page w/ additional query parameters. Fixed that and updated the comment
about why the page does not need to be re-loaded if the only query
parameter passed in is `email`

shane-tomlinson/fxa-content-server,mozilla/fxa-content-server,mozilla/fxa-content-server,shane-tomlinson/fxa-content-server,mozilla/fxa-content-server,shane-tomlinson/fxa-content-server