refactor(verification): externalize verification dependencies [part 1/2]

[glevco]

Depends on #896

Motivation

This PR introduces the concept of verification dependencies. Before, to perform verifications, it was necessary to retrieve data from the vertex itself and also from multiple other sources, for example from the TransactionStorage.

Now, instead of doing this dependency retrieval one by one, interspersed in the whole verification process, a single point retrieves all necessary dependencies and everything is verified from the vertex data plus those pre-calculated dependencies. This prevents unnecessary duplicate calculations, and will be necessary for the Multiprocess Verification project.

There are also some other side-benefits:

• This is one step forward in completely removing the TransactionStorage from inside vertices.
• Sync-v2 may verify vertices using dependencies from its memory instead of the TransactionStorage (as discussed here).
• Improved typing and ergonomics of VerificationService methods.

Note: in this PR, not all ad-hoc dependencies have been moved yet. This will be completed in the next PR.

Acceptance Criteria

• Create new verification dependency models that are pre-calculated before verification.
• Update verifiers to use dependency models instead of directly accessing storage.
• Add new auxiliary methods to SimpleMemoryStorage.

Checklist

• If you are requesting a merge into master, confirm this code is production-ready and can be included in future releases as soon as it gets merged

[codecov]

Codecov Report

Attention: Patch coverage is 97.68786% with 4 lines in your changes are missing coverage. Please review.

❗ No coverage uploaded for pull request base (refactor/feature-activation/enable-usage@96c6ab0). Click here to learn what that means.

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Files	Patch %	Lines
...athor/transaction/storage/simple_memory_storage.py	94.00%	3 Missing ⚠️
hathor/verification/block_verifier.py	90.90%	1 Missing ⚠️

Additional details and impacted files

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##             refactor/feature-activation/enable-usage     #859   +/-   ##
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[msbrogli]

I think we can simplify it a lot by just implementing a simple memory database.

class SimpleMemoryDB:
    def __init__(self):
        self._db: Dict[VertexId, BaseTransaction] = {}

    def add_vertex(self, vertex: BaseTransaction) -> None:
        self._db[vertex.hash] = vertex

    def get_vertex(self, _id: VertexId) -> BaseTransaction:
        return self._db[_id]

It might have support for metadata too if needed.

[glevco]

This PR was completely changed, so I recommend re-reviewing it. Indeed the SimpleMemoryDB was a good solution for tx parents and spent txs, and I implemented it. But I needed to keep the verification model abstractions for some other dependencies.

[glevco]

@jansegre @msbrogli requested re-review after rebase with conflicts.

EDIT: I also added a new commit fixing a performance regression that I found.

[glevco]

Moved to PRs #1022 and #1023.