EVM/Kernel: store chain id in rollup

Context

When we officialy deploy the rollup we'll need to have unique chain_id, that will require only to change the constant declaration in the kernel.

Manually testing the MR

You can try to replace the EVM proxy value with a random value and inject a transaction with MetaMask, the transaction should be ruled out.

You can always manually test merge request by playing with the debugger:

$ make -f kernels.mk evm_kernel.wasm
$ rlwrap ./octez-smart-rollup-wasm-debugger evm_kernel.wasm --inputs tezt/tests/evm_kernel_inputs/inputs.json

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