EVM: move basic,address,signatures to ethereum crate

Context

The end goal is to share as much code as possible between [evm_execution] and [kernel]. To go in this direction, my proposal is to structure the project as:

• evm_execution: everything related to SputnikVM and transaction execution
• ethereum: every types declarations needed for EVM (probably not wasm-pvm specific, i.e. no storage?)
• kernel: blockchain kernel

In a dependency graph you'll have:

            kernel
          /        \
         /          \
   evm_execution     \
         \            \
          \           / 
           \         /
            ethereum
          

It should not change semantics at all, it's just changing the structure.

Temporary ownership of this MR: @rodibozman

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CI

Checklist

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