iks: add ProbeType class that wraps Szarp enum

+ add class that represents probe type. Currently custom probe length
  is not supported.
+ change SzbaseWrapper to use ProbeType in szarp calls
iks: missing header
iks: Param class supports multiple values

+ cause in szarp we can ask server about couple different probe types
  Param class now allows to set one value for each ParamType
+ server is now sending value with information about probe type. In case
  of 10 seconds probes command is the same, but in case of average
  information about probe type is added. So it can look like this:

    v 0 Param 17
    v 0 Param 17.3 10m
    v 0 Param 18.1 1h
iks: add probe type handling to set subscription

+ now while subscribing one must specify probe type he want subscribe on.
  This changes subscribe command a bit:

    set_subscribe <ID> "Some set" 10m 5239903430201691473

+ and after this only updates about 10m average values are sent to
  this client.
iks: values update optimisation

+ call update checker as rare as possible