feat: implement create_engine

[tamaralipows]

Task

Unforeseen changes:

• Needed to factor out the init_account into a Trait implemented by both SimulationDB and TychoDB in order to keep the simulation engine creation generalized. More information in this slack thread.
• We are not able to eliminate mentions of DatabaseRef here since the SimulationEngine.simulate method requires this trait when initializing the builder

        let default_builder = Evm::builder()
            .with_spec_id(SpecId::CANCUN)
            .with_ref_db(db_ref) <----------------- we cannot change this.
            .with_block_env(block_env)
            .with_tx_env(tx_env);

Notes:

We plan on creating a more thorough integration test after finishing the sprint goals (which will leave us with everything necessary for creating the integration test). This is why we are not wasting too much time integration-testing the engine and ProtoSim/Adapter contracts. The test in the engine for this PR simply checks that the call to init_account succeeds with the expected types.

[dianacarvalho1]

Thank you so much @tamaralipows 🙏🏼 This looks good, I like it! I only have small questions/suggestions!

[zizou0x]

Very interesting, why was this needed? What does it breaks if the mock db isn't Send or Sync?

[tamaralipows]

The usage of Arc for the test:

warning: usage of an `Arc` that is not `Send` and `Sync`
   --> src/protocol/vm/engine.rs:138:18
    |
138 |         let db = Arc::new(RwLock::new(MockDatabase::default()));
    |                  ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
    |
    = note: `Arc<RwLock<MockDatabase>>` is not `Send` and `Sync` as `RwLock<MockDatabase>` is not `Sync`
    = help: if the `Arc` will not used be across threads replace it with an `Rc`
    = help: otherwise make `RwLock<MockDatabase>` `Send` and `Sync` or consider a wrapper type such as `Mutex`
    = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#arc_with_non_send_sync
    = note: `#[warn(clippy::arc_with_non_send_sync)]` on by default

[zizou0x]

FYI, it's not send and sync because you used a RefCell here

If you change this to be something like a Mutex then you don't need this unsafe code

Also please note that these two lines are really dangerous and should never be used in the program code

[dianacarvalho1]

Yeeesss looks good 🙏🏼 ✨ Thank you thank you!

[propellerci]

This PR is included in version 0.25.0 🎉