SLS limitation task

[vetss]

We may have an issue of different representation of SLS max size. This is some mess, needed to optimize it.
SLS max size may be (from org.restcomm.protocols.ss7.mtp.RoutingLabelFormat)
16 (ITUT), 32 or 256 (ANSI).

We have different places where the value is presented.

• RoutingLabelFormat Mtp3UserPartBaseImpl.routingLabelFormat (MTP level) - not used at all
• int AspFactoryImpl.maxSequenceNumber - used for slsTable preparing (there is a root value for it in m3ua stack). slsTable is for selecting of SCTP streamNumber
• int SccpStackImpl.slsFilter - (hardcoded 0xF) - for slsTable, there is also a local variable "maxSls = 16" - used for msgDeliveryExecutors for local SCCP user delivering.