fix: refactoring the token metadata cache to become a globally accessible

[geekbrother]

Description

This PR refactors the tokens metadata cache to be globally accessible by the TokenMetadataCacheProvider to fix the cache inconsistency between different providers and metadata caching implementations between providers.

How Has This Been Tested?

Current balance and history integration tests should pass.

Due Diligence

• Breaking change
• Requires a documentation update
• Requires a e2e/integration test update

[Copilot]

Pull Request Overview

This PR refactors the tokens metadata caching mechanism to make it globally accessible via the TokenMetadataCacheProvider interface. Key changes include removing the token_metadata_cache field from the AppState, updating cache-related method signatures across providers and handlers, and implementing a new TokenMetadataCache that conforms to the TokenMetadataCacheProvider trait.

Reviewed Changes

Copilot reviewed 11 out of 11 changed files in this pull request and generated no comments.

Show a summary per file

File	Description
src/state.rs	Removed token_metadata_cache from AppState and its associated instantiation in new_state.
src/providers/zerion.rs	Updated cache interface usage in BalanceProvider and HistoryProvider implementations to use TokenMetadataCacheProvider.
src/providers/solscan.rs	Switched to the new TokenMetadataCacheProvider interface and adjusted error logging and metadata handling.
src/providers/one_inch.rs	Modified the get_price signature to accept a TokenMetadataCacheProvider argument.
src/providers/mod.rs	Introduced the TokenMetadataCacheProvider trait and updated provider traits and repository initialization.
src/providers/dune.rs	Replaced the legacy cache functions with the new TokenMetadataCacheProvider methods and updated error handling.
src/providers/coinbase.rs	Changed the get_transactions signature to use the new TokenMetadataCacheProvider interface.
src/lib.rs	Removed initialization of token_metadata_cache from the bootstrap and updated dependency injections.
src/handlers/history.rs	Updated transactions handler to pass token_metadata_cache from the providers repository.
src/handlers/fungible_price.rs	Updated fungible price handler to pass token_metadata_cache, in line with the new cache interface.
src/handlers/balance.rs	Removed legacy caching functions, updated cache TTL type, and implemented a new TokenMetadataCache struct.

Comments suppressed due to low confidence (2)

src/providers/solscan.rs:307

• [nitpick] Consider using '{}' as the placeholder (e.g. error!("Error when setting token metadata in cache: {}", e)) for consistency with other error logs.

error!("Error when setting the token metadata to the cache: {e}");

src/handlers/balance.rs:441

• Typo in the error message: 'seting' should be corrected to 'setting'.

cache.set_ex(key, value, ttl).await.map_err(|e| StorageError::Connection(format!("Error when seting cache: {e}")))?;