sysdb: sanitize search filter input
    
    This patch sanitizes the input for sysdb searches by UPN/email, SID and
    UUID.
    
    This security issue was assigned CVE-2017-12173
    
    Resolves:
    https://pagure.io/SSSD/sssd/issue/3549
    
    Reviewed-by: Lukáš Slebodník <lslebodn@redhat.com>
    Reviewed-by: Jakub Hrozek <jhrozek@redhat.com>
    (cherry picked from commit 1f2662c8f97c9c0fa250055d4b6750abfc6d0835)