Add SLA pausing, SLA reports, SLA filtering and kanban SLA state (phase 3)

Statuses can be flagged to pause the resolution clock; sla_history records the intervals a ticket's clock actually ran and the deadline is re-based on remaining budget when it resumes. Adds SLA Summary and SLA by Client reports, an SLA state filter on the ticket list, SLA colouring on kanban cards, and an Urgent column on the Tickets by Client report. DB update 2.5.1. Also fixes resolution SLA verdicts being skipped when resolving via kanban or the client portal.

cron/cron.php

@@ -484,6 +484,7 @@ while ($row = mysqli_fetch_assoc($sql_resolved_tickets_to_close)) {
     $client_id = intval($row['ticket_client_id']);
 
     mysqli_query($mysqli,"UPDATE tickets SET ticket_status = 5, ticket_closed_at = NOW(), ticket_closed_by = $ticket_assigned_to WHERE ticket_id = $ticket_id");
+    syncTicketSlaClock($ticket_id);
 
     //Logging
     logAudit("Ticket", "Closed", "$ticket_prefix$ticket_number auto closed", $client_id, $ticket_id);