[BUGFIX] "Suggest" should respect allowedSites for siteHashFilter

The suggest eID script should use/respect the
setting search.query.allowedSites when
calculating a site hash for a query.

This is default behavior for the normal
search page and should be the same in
the suggest script

Change-Id: I35ea287a9cce7c75f74bad53c94c1f06d65682ba
Resolves: #54862
Reviewed-on: https://review.typo3.org/26715
Reviewed-by: Soren Malling
Tested-by: Soren Malling
Reviewed-by: Ingo Renner
Tested-by: Ingo Renner