Implement AccountComponents

[PhilippGackstatter]

TODO

closes #935

[bobbinth]

Looks good! Thank you! Not a review, but I took a quick look and left some comments inline.

[bobbinth]

Not for this PR, but one thing that may be good to add here is a filed which specifies whether the component is valid for all accounts or only for special type of accounts (e.g., a fungible faucet). This way, we can prevent errors when trying to add non-faucet components to faucets etc.

Let's create an issue for this.

[bobbinth]

On the other hand, if it is not too difficult, we may consider doing it in this PR as it may simplify account construction as mentioned in #941 (comment).

[PhilippGackstatter]

I added an AccountComponentType::{Faucet, Any} now to address this. I'm not sure if Any is correct or sufficient though. Some components like authentication can be added to any account, so it seems correct to have it there. But maybe a third category like Regular (or something more descriptive) is needed for things like BasicWallet?
Then any account instantiated from multiple components would fail if any Faucet and Regular components are mixed?

[bobbinth]

Another way to do this could be to use a BTreeSet<AccountType> and explicitly specify the types of account a component can be applied to. Then, we can have convenience methods like is_valid_for(account_type) and is_only_for_faucet().

[bobbinth]

Once everything is ready, this will replace AccountCode::new(), right?

[PhilippGackstatter]

Yes, it's replaced almost everywhere now, only internal references left to cleanup 👍

[bobbinth]

We also need to check that the offset does not exceed 255 (I believe) as this is the maximum number of storage slots per account.

[bobbinth]

This will replace Account::new() right?

Also, a couple of thoughts:

• If we have a way to infer account type from the underlying components (i.e., if it is a faucet or not), we can avoid passing it as a parameter.
• If we do pass account type as a parameter, we need to add a check to make sure the generated ID matches this type.

[bobbinth]

Potentially, I'd move this logic into the account constructor.

[PhilippGackstatter]

I agree that would be nice, but given the dependence of the AccountId on the code and storage, I don't know how we could efficiently rewrite places like these:

miden-base/miden-lib/src/accounts/faucets/mod.rs

Lines 105 to 116 in 4cf0185

	let account_code = AccountCode::from_components(&components)?;
	let account_storage = AccountStorage::from_components(&components)?;
	let account_seed = AccountId::get_account_seed(
	init_seed,
	AccountType::FungibleFaucet,
	account_storage_mode,
	account_code.commitment(),
	account_storage.commitment(),
	)?;
	let account = Account::new(account_seed, account_code, account_storage)?;

We can of course call Account::from_components on the same components again, but that will redo work we've just done (including MastForest::merge which is expensive).