feat(dataset-store): support loading datasets by name and version

[LNSD]

Context and Rationale

This is an important rewrite of the DatasetStore struct.

• New ManifestsStore Module: Created a dedicated module to handle all manifest operations. It communicates with both the object store and the metadata database to maintain synchronization.

• Dataset Store Initialization: When the init() method is called, the dataset store lists all manifest files in the manifest store and registers them in the metadata database. The dataset name and version are extracted from the filename. If the filename doesn't include a version suffix, it defaults to v0.0.0. If not explicitly initialized, the dataset store and manifest store are lazily initialized on first use.

• Loading Datasets by Version: One can now load datasets with or without specifying a version. If a version is not provided, it automatically resolves the latest version from all the dataset versions registered in the metadata DB.

• Direct Type Deserialization: Got rid of the ManifestValue wrapper that used to sit between TOML/JSON and our actual types. Now we deserialize manifests directly into the structs we need, which is cleaner and less prone to errors.

• Typed Provider Configs: Provider configurations are no longer generic TOML blobs. Each extractor now has its own config struct (EvmRpcProviderConfig, FirehoseProviderConfig, SubstreamsProviderConfig, EthBeaconProviderConfig) with clearly defined fields.

• Better Error Messages: Instead of generic errors, we now have specific error types for each operation (RegisterManifestError, GetDatasetError, GetLatestVersionError, IsRegisteredError). This makes debugging easier.

Commit message

feat(dataset-store): support loading datasets by name and version

Refactored the dataset store to load datasets by name with optional version, making version management easier and cleaning up the manifest handling.

• Introduced ManifestsStore module for centralized manifest management with MetadataDb integration
• Added versioned dataset loading with automatic latest version resolution when version not specified
• Removed ManifestValue abstraction in favor of direct strongly-typed manifest deserialization
• Extracted provider configurations into dedicated typed structs (ProviderConfig) for each extractor
• Added init() method to sync object store manifests with metadata database on startup

[fubhy]

Can confirm that the typescript client side works with this change.