Properly join on action.parentid wrt service id and its type.

Compare:

WRONG:

 SELECT a1.parentid, c.id, s.type, s.id, s.parentid
 FROM casetbl c, servicetbl s, actiontbl a1
 WHERE (a1.result='serviceOrdered'
      OR a1.result='serviceOrderedSMS')
 AND a1.name='orderService'
 AND cast(split_part(a1.parentid, ':', 2) as integer)=s.id
 AND cast(split_part(a1.caseid, ':', 2) as integer)=c.id
 AND c.city = 'Moskva'
 AND c.calldate >= (CURRENT_DATE - INTERVAL '2 days');

RIGHT:

 SELECT a1.parentid, c.id, s.type, s.id, s.parentid
 FROM casetbl c, servicetbl s, actiontbl a1
 WHERE (a1.result='serviceOrdered'
      OR a1.result='serviceOrderedSMS')
 AND a1.name='orderService'
 AND a1.parentid=concat(s.type, ':', s.id)
 AND cast(split_part(a1.caseid, ':', 2) as integer)=c.id
 AND c.city = 'Moskva'
 AND c.calldate >= (CURRENT_DATE - INTERVAL '2 days');

This does not actually affect processing times calculation, still we
change it for consistency.
Calculate average towing time using action chain creation time, not the
call time (#516)