refactor: replace ipfs TimeSizedCache with Moka

[metalurgical]

Description

Replace the existing mutex IPFS cache with Moka.

Changes

• Replace Mutex<TimedSizedCache<AppDataHash, Option<String>>> with moka::future::Cache<AppDataHash, Option<String>>
• Remove manual cache locking
• Preserve existing cache size and expiration
• Reduce stampede likelihood (though not entirely eliminated), concurrent fetches for the same key share a single IPFS request (see try_get_with())

How to test

cargo nextest run

[gemini-code-assist]

Code Review

This pull request replaces the cached crate with moka for caching IPFS app data in the orderbook, which simplifies the code by removing explicit Mutex locking. It also updates a test assertion in the balance overrides crate. The review feedback suggests using moka::future::Cache instead of moka::sync::Cache to perform non-blocking operations in an asynchronous context.

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