[BUGFIX] Query parameters of external link may get altered

If an external link is set to the same domain as the BE domain and
the id query parameter is present, any other query parameters will
be altered (and repeated).
Solution: href of external link should remain unaltered.

Resolves: #47844
Releases: 6.0, 6.1, 6.2
Change-Id: I79564ebf63ee4f92bfd3f95b17f72592ea849163
Reviewed-on: https://review.typo3.org/22682
Reviewed-by: Wouter Wolters
Tested-by: Wouter Wolters
Reviewed-by: Philipp Gampe
Tested-by: Philipp Gampe