Bolt-cli: Add dry-run flag for developmental/testing

[0ex-d]

Improvements:

• Add -d, --dry-run flag for bolt-cli: When provided commands will "simulate" actual behavior, for instance when making RPC calls or executing smart contracts without broadcasting on net.
• Spin Anvil instance for use cases like testing (we can get rid of explicit declaration in test):
  

  bolt/bolt-cli/src/commands/validators.rs

  Lines 165 to 171 in 6342fb2

  	async fn test_register_validators() {
  	let _ = tracing_subscriber::fmt::try_init();
  	let rpc_url = "https://holesky.drpc.org";
  	let anvil = Anvil::default().fork(rpc_url).spawn();
  	let anvil_url = Url::parse(&anvil.endpoint()).expect("valid URL");
  	let provider = ProviderBuilder::new().on_http(anvil_url.clone());

Closes #416

[0ex-d]

Hi @merklefruit, just checking in on this PR. Let me know if any changes are needed. Looking forward to your feedback. Thanks!

[merklefruit]

Great work here! Really sorry about the delay. Thanks a lot for the contribution!

I left a couple nits :)

[merklefruit]

lgtm, thanks!