Similar to https://github.com/FreeOpcUa/python-opcua/pull/945
Small test: https://pastebin.com/SxUSnFi0

* replace set/get_value(s) methods with read/write_value(s) and write to get closer to spec

* now you can limit the max amount of connections

* changed the discussed code

jonasgreen88 : fix token

Don't cancel missing subscription task

This allows consumers of the library to set buildinformation.
Additionally this fixes buildinformation representation in individual
nodes (like ua.ObjectIds.Server_ServerStatus_BuildInfo_ProductUri).
Before the individual buildinfo nodes haven't been populated. Now,
they are kept in sync with the buildinfo struct.

Calling `sync.Server.get_node` raises an `AttributeError`.
This commit fixes the issue and adds a corresponding test.

* Resolve collections.Iterable DeprecationWarning

* Import from collections.abc

Await connection lost tasks when stopping internal server

According to OPC Unified Architecture, Part 5, 6.3.11
OperationLimitsType all Max* properties shall have datatype
UInt32.

Fix this by explicitly setting the variant type to UInt32
instead of defaulting to Int64.

This fixes connectivity issues with the KepwareServerEx OPC-UA client.

Introduced in 21432df9

Allow Asynchronous Method Calls

add conditional requirement as per https://pypi.org/project/pytest-runner/ conditional requirements instructions