feat: fetch gasless transactions for BatchSell quotes

[micaelae]

Explanation

Implements the updateBatchSellTrades handler which calls the obtainGaslessBatch to estimate network fees for BatchSell quotes. Clients will need to call the handler whenever the selectBatchQuotes selector's recommended quotes change

A new selector selectBatchSellTrades has also been added, which returns whether a batch is submittable, and the totalNetworkFee provided by the obtainGaslessBatch endpoint and its converted values

References

Fixes https://consensyssoftware.atlassian.net/browse/SWAPS-4444

Checklist

• I've updated the test suite for new or updated code as appropriate
• I've updated documentation (JSDoc, Markdown, etc.) for new or updated code as appropriate
• I've communicated my changes to consumers by updating changelogs for packages I've changed
• I've introduced breaking changes in this PR and have prepared draft pull requests for clients and consumer packages to resolve them

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Note

Medium Risk
Adds a new network call and state flow for BatchSell fee/transaction batch fetching, including abort/error handling and breaking selector output changes. Risk is moderate due to new API integration and fee display/submittability gating logic.

Overview
BatchSell quotes now have a separate fetch path for gasless transaction batches and fees. BridgeController adds updateBatchSellTrades, stores results in new state fields (batchSellTrades, batchSellTradesLoadingStatus), and aborts in-flight requests on new quote requests/resets to avoid stale fee data.

Selectors and API/types were updated to support this flow. selectBatchSellQuotes no longer returns totalNetworkFee (breaking); new selectBatchSellTrades derives totalNetworkFee from the obtainGaslessBatch response (with exchange-rate conversion) and reports whether the batch is submittable based on fetched transactions.

Validation/test coverage expanded. Adds request/response formatting + strict validators for batch responses and gasless fee fields, updates snapshots, and removes unnecessary Hex type assertions in bridge transaction construction.

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