Remove usage of xs:nonNegativeInteger

It has turned out that the type xs:nonNegativeInteger is not supported by Microsofts xsd.exe. Therefor the usage of this type is disencouraged. One would in general only really need this type for values that can be unlimitedly large. As we dont really need this we can replace. The suggested replace is xs:unsignedLong which xsd.exe correctly translates to ulong.

The replacement in particular should work via changing tCounter to unsignedLong and other nonNegativeIntegers to tCounter. (Discussion with TN: https://railmlorg.slack.com/archives/D0551E9P07L/p1738675485905839?thread_ts=1738600113.271179&cid=D0551E9P07L)