Url aliases are sanitized at creation time. But at lookup time, the requested urlalias is not sanitized. This prevents us from generating certain custom URLs with special characters inside. This may be related to EZEE-2926

Steps to reproduce:

1. Create a page
2. Create an url alias '/schülerwettbewerb'
3. The alias is created as '/schuelerwettbewerb'
4. open http://localhost/schülerwettbewerb
5. See a 404 instead of the created page