Multivm tests for era_vm

[MarcosNicolau]

What ❔

This pr makes the necessary changes to test the era_vm integration with the bootloader:

• Adds a basic tester module for managing the tests and comparing final states with the original vm.
• Adds the most basic bootloader test to check that everything works.

To run the tests do: cargo test era_vm under core/lib/multivm. You should see:

running 4 tests
test versions::era_vm::transaction_data::tests::test_consistency_with_encoding_length ... ok
test versions::era_vm::bootloader_state::utils::tests::test_basic_pubdata_building ... ok
test versions::era_vm::tests::bootloader::test_bootloader_out_of_gas ... ok
test versions::era_vm::tests::bootloader::test_dummy_bootloader ... ok

test result: ok. 4 passed; 0 failed; 0 ignored; 0 measured; 143 filtered out; finished in 0.83s

This pr depends on the adaptation on era_vm, see here.

Checklist

• PR title corresponds to the body of PR (we generate changelog entries from PRs).
• Tests for the changes have been added / updated.
• Documentation comments have been added / updated.
• Code has been formatted via zk fmt and zk lint.

[MarcosNicolau]

This pr has grown and now should include the fixes for all remaining tests. The following changes have been made to the era_vm bootloader:

• Implements get_current_execution_state.
• Returns vm execution logs and statistics in inspect.
• Implements refunds.
• Implements all remaining hooks: PubdataRequested, AskOperatorForRefund, PostResult and NotifyAboutRefund.
• Implements snapshots and rollbacks.

This make all tests pass except for:

• transfer: the two of them.
• refunds: only test_predetermined_gas_refund.
• simple_execution.

I believe these tests have little to do with the bootloader, I think we are doing something wrong on the era_vm.