Use the protocol version inside a network connection profile and throw and exception when it's not 2.0.1

[WilcodenBesten]

OCPP Version

OCPP2.0.1

Describe the problem

Currently, libocpp does not check the OCPP version in a network connection profile, but assumes that all profiles are OCPP 2.0.1. This should be handled properly, as this can definitely happen in the field, for example when trying to migrate a station from an OCPP 1.6 CSMS to an OCPP 2.0.1 CSMS.

Describe your solution

After some discussion in Zulip we decided that there should be a proper implementation within the library to handle different protocol versions and switch between them.

For now, we add an exception when libocpp selects the next network connection profile that has a protocol version other than 2.0.1. It's up to the application side to handle this correctly. This is optional, as you can still use the `validate_network_profile_callback' to prevent network profiles with a protocol version other than 2.0.1 from being set.

Additional context

No response