L2/Node/Kernel: Parametrize the safe storage in the Kernel and store Tezlink blocks at Tezlink root instead of Etherlink root

What

Parametrize the safe storage mechanism with a path. Instead of having /evm/world_state as a constant, it comes now from the chain configuration

Why

The safe storage is a mechanism that protects the kernel, if something failed during a kernel run (a real kernel error not just a transaction), it's not a problem as from the beginning of the produce function we were writing at /tmp/evm/world_state instead of /evm/world_state so revert the changes are easy.

But for tezlink, things are not written at /evm/world_state but at /tezlink, as things are right now safe storage is fixed to /evm/world_state which means that we don't benefit of the safe_storage

How

Manually testing the MR

Checklist

• Document the interface of any function added or modified (see the coding guidelines)
• Document any change to the user interface, including configuration parameters (see node configuration)
• Provide automatic testing (see the testing guide).
• For new features and bug fixes, add an item in the appropriate changelog (docs/protocols/alpha.rst for the protocol and the environment, CHANGES.rst at the root of the repository for everything else).
• Select suitable reviewers using the Reviewers field below.
• Select as Assignee the next person who should take action on that MR