use dataclasses for all ua structures

[oroulet]

If I even manage to finish that PR it will be a bif code size reduction and hopefully some performance improvments BUT a big low level API change https://github.com/FreeOpcUa/opcua-asyncio/pull/420/files

The idea is to replace all customs __str__, __repr__, __eq__, __init__methods and remove ua_types and maybe __ua_switches__in all ua structures using dataclass decorator.
Also using frozen=True, the structures becoes 'almost' immutable resulting in some memory saving, and will avoid many typos BUT the immutable structures will change how structs are created from

s = ua.StatusCode()
s.value = 1

to

s = ua.StatusCode(Value=1)

[oroulet]

implemented there: #420

[oroulet]

simplifies a lot of code (reduce almost half of autogenerated code), makes all struct classes behave the same, allow us to benefit from dataclass improvments in the futures (they are working on performance), better API. We can now write AddNodeItem(arg1, ar2, arg2) and hopefully can we enable frozen=True in the future that will also increase performance and remove a bunch of very common errors.