Fix EZP-23517: Excluded uri prefixes result in redirect loop

> https://jira.ez.no/browse/EZP-23517

`URLAliasRouter::needsCaseRedirect()` didn't check if requested path was excluded from content tree jail.

Added a test.
Cleaned up UrlAliasRouterTest
Merge pull request #1078 from ezsystems/fix_EZP-23517_redirectLoopUriPrefixExcluded

Fix EZP-23517: Excluded uri prefixes result in redirect loop