Restrict write_registers etc to list[int].

[janiversen]

Typing in python is really BAD !!

every developer would read this:

   values: list[int] | list[bytes]

as values can be either list[int] OR list[bytes], but mypy is stupid and requires values to be "list[int] | list[bytes]"

Using:

   values: Sequence[int | bytes]

solves this problem, but do NOT allow the array to be changed.

As a consequence of this, the API from now on only accept list[int], which are NOT modified !!

If an app wants to use bytes, it must be converted to int before calling. The API contains different from/to register conversions that can help if needed.