EVM Node: Call `Random.self_init ()` from the binary

Libraries should not setup runtime components like the Random state. This is commonly viewed as a bad practice: what if two libraries setup the same components differently? Or, we can imagine tests wanting to set up a reproducible Random state, instead of relying on /dev/urandom.

As a consequence, we move the Random.self_init call in bin_node main module, as it is done for instance for the Octez node.

Manually testing the MR

Should be a no-op change.

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