Tests: Add `case_filterParsing`
Tests: Add `case_filterParsing`

This also makes clear how legacy filter are supposed to be treated.

Signed-off-by: Niklas Hambuechen <98215d3a72cb13cc9c9956528e50119ca7d1fb8b@google.com>
Signed-off-by: Klaus Aehlig <4ce51de36d9068cd7db2eec1151e0f3f95419008@google.com>
Reviewed-by: Klaus Aehlig <4ce51de36d9068cd7db2eec1151e0f3f95419008@google.com>

leshchevds/ganeti,grnet/snf-ganeti,mbakke/ganeti,ganeti/ganeti,yiannist/ganeti,onponomarev/ganeti,ganeti-github-testing/ganeti-test-1,leshchevds/ganeti,ganeti/ganeti,ganeti/ganeti,mbakke/ganeti,grnet/snf-ganeti,ganeti-github-testing/ganeti-test-1,apyrgio/ganeti,andir/ganeti,bitemyapp/ganeti,andir/ganeti,dimara/ganeti,mbakke/ganeti,yiannist/ganeti,apyrgio/ganeti,onponomarev/ganeti,dimara/ganeti,yiannist/ganeti,leshchevds/ganeti,andir/ganeti,bitemyapp/ganeti