Consider dissect.cstruct as eRPC parser for python

[Hadatko]

We can consider, using this module https://github.com/fox-it/dissect.cstruct, replace shim code for structs (later unions, ...) on python side. They are preparing new version of module which i hope will support far more options. And looks like they are open for contribution into their repository if we will have a will.

For the future the idea is to reduce shim code in way that unions and structures would be parsed via this module, which can radically simplified erpc code generator on python side.