EVM: Versioning encodings

This is a meta issue on how to version current encodings in the EVM Kernel if they need to be changed. The process is described in https://docs.google.com/document/d/1t0yTd6-Zp79xhPLQEROY-Ob5aP6xMgUSwb8Rw1eJ4I8

The following discussion from !11897 (merged) should be addressed:

• @picdc started a discussion:

  Idea for an improvement: It would be useful to version the encoding. For example by wrapping the whole RLP encoded value into an RLP list as: [version, data], wherre data's encoding depends on the version (obviously, but I like restating the facts). The kernel will only support a version but the node can have multiple encodings so that it can handle upgrades a bit more smoughly. I didn't implement it in this MR directly but it would make sense for a later one.