Make shipping methods revisionable to track changes

Problem/Motivation

If the shipping methods will not be changed into config entities, it would make a lot of sense to allow them to be revisioned to be able to track changes. If something is wrong, then you'll be able to reset to the previous state and track what whas changed when.

As shipping methods are quite complex sometimes, this safetly net would be extremely helpful.

Steps to reproduce

Proposed resolution

Remaining tasks

User interface changes

API changes

Data model changes