Initial interface for contract calls

[digorithm]

Introduces an interface contract calls. Right now it only performs very basic calls to contracts and scripts deployment + execution (scripts not related to contracts).

Contract calls can be done like this:

let (_, contract_id) = Contract::launch_and_deploy(&compiled_contract, true)
      .await
      .unwrap();

  // Call contract
  let utxo_id = Bytes32::from([0u8; 32]);
  let balance_root = Bytes32::from([0u8; 32]);
  let state_root = Bytes32::from([0u8; 32]);
  let gas_price = 0;
  let gas_limit = 1_000_000;
  let maturity = 0;
  let input_index = 0;

  let receipts = Contract::call(
      contract_id,
      utxo_id,
      balance_root,
      state_root,
      input_index,
      gas_price,
      gas_limit,
      maturity,
  )
  .await
  .unwrap();

  assert_eq!(true, receipts.len() > 0);

And simple script execution from within the SDK, like this:

// Compile the script we will be calling
  let compiled =
      Script::compile_sway_script("../fuels-abigen-macro/tests/test_projects/simple_script")
          .unwrap();

  let tx = Transaction::Script {
      gas_price: 0,
      gas_limit: 1_000_000,
      maturity: 0,
      receipts_root: Default::default(),
      script: compiled.raw, // Here we pass the compiled script into the transaction
      script_data: vec![],
      inputs: vec![],
      outputs: vec![],
      witnesses: vec![vec![].into()],
      metadata: None,
  };

  let script = Script::new(tx, constants::DEFAULT_NODE_URL.to_string());

  let result = script.call().await.unwrap();

You can jump straight to fuels-rs/tests/calls.rs to see how it works.

The next step is to bind this interface to the functions generated by the abigen! and craft script_data on the fly in order to call specific functions from a deployed contract.

Closes #4.

[AlicanC]

LGTM

[Voxelot]

Suggested change

	let salt: [u8; 32] = rng.gen();
	let salt = Salt::from(salt);
	let salt: Salt = rng.gen();

[digorithm]

Tried that before doing the ugly way, was getting this:

[digorithm]

I will figure this out on the next PR I'll be submitting soon, need to merge this 😅.