EVM/Kernel: use panic_handler

Context

It's a really nice feature :).

Manually testing the MR

Add some random panics in the code and play in the debugger:

$ rlwrap ./octez-smart-rollup-wasm-debugger evm_kernel.wasm --inputs inputs.json
load inputs
Loaded 2 inputs at level 0
step inbox
Genesis block was initialized.
Blueprint 0 contains 2 transactions.
Block  at number 1 contains 2 transaction(s).
Kernel panic Some("fooooo") at Some(Location { file: "kernel/src/lib.rs", line: 104, col: 5 })

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