fix(sidecar): don't mutate account_state on template refresh

[thedevbirb]

Closes #505.

The problem wasn't related to missed slot this time but the logic of refreshing templates.

bolt/bolt-sidecar/src/state/execution.rs

Lines 507 to 525 in edaec29

	fn refresh_templates(&mut self) {
	for (address, (account_state, _)) in self.account_states.iter_mut() {
	trace!(%address, ?account_state, "Refreshing template...");
	// Iterate over all block templates and apply the state diff
	for template in self.block_templates.values_mut() {
	// Retain only signed constraints where transactions are still valid based on the
	// canonical account states.
	template.retain(*address, *account_state);
	// Update the account state with the remaining state diff for the next iteration.
	if let Some((nonce_diff, balance_diff)) = template.get_diff(address) {
	// Nonce will always be increased
	account_state.transaction_count += nonce_diff;
	// Balance will always be decreased
	account_state.balance -= balance_diff;
	}
	}
	}
	}

It should not iter_mut over the account_states but rather copying it, which is cheap since it AccountState implements Copy.
By mutating it, if two inclusion requests are made for the same target_slot but during different slots, then the validation fails because the account state has wrong nonce due to adding block templates nonce and balance diffs to it.

A test to cover this case has been introduced.
Tested on devnet as well

[mempirate]

Nice catch