feat(utils): add fast iterable map

[omri-ba-starkware]

This change is 

[MohammadNassar1]

@MohammadNassar1 reviewed 2 of 2 files at r1, all commit messages.
Reviewable status: all files reviewed, 4 unresolved discussions (waiting on @RoeeGross)

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packages/utils/src/storage/fast_iterable_map.cairo line 32 at r1 (raw file):

    _initialized_map: Map<K, bool>,
    _head: K,
    _tail: K,

Can you please explain why you need to store the tail?

Code quote:

    _head: K,
    _tail: K,

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packages/utils/src/storage/fast_iterable_map.cairo line 58 at r1 (raw file):

        self._length.read()
    }
}

I think you can use as_non_mut instead

Code quote:

impl StoragePathMutableFastIterableMapImpl<
    K, V, +Drop<K>, +Drop<V>, +Store<V>, +Hash<K, HashState>,
> of FastIterableMapTrait<StoragePath<Mutable<FastIterableMap<K, V>>>> {
    type Key = K;
    fn len(self: StoragePath<Mutable<FastIterableMap<K, V>>>) -> u64 {
        self._length.read()
    }
}

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packages/utils/src/storage/fast_iterable_map.cairo line 79 at r1 (raw file):

    type Key = K;
    type Value = V;
    fn read(self: StoragePath<FastIterableMap<K, V>>, key: Self::Key) -> Option<Self::Value> {

StorageMapReadAccess trait returns Value, and not Option.

Code quote:

Option<Self::Value>

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packages/utils/src/storage/fast_iterable_map.cairo line 84 at r1 (raw file):

        } else {
            Option::None
        }

I think match is better here.

Code quote:

        if self._initialized_map.entry(key).read() == true {
            Option::Some(self._inner_map.entry(key).read().value())
        } else {
            Option::None
        }