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 obtainGaslessBatch fetch flow with new controller state and abort/error handling, plus a breaking selector output change for BatchSell fee data. Risk is moderate because it affects quote-refresh behavior and client integrations that previously read fees from selectBatchSellQuotes.

Overview
Adds first-class support for BatchSell gasless transaction batches and fee estimation by introducing BridgeController:updateBatchSellTrades, which calls the obtainGaslessBatch endpoint, tracks loading/error state, aborts stale in-flight requests, and resets batch data on new quote requests or resetState.

Introduces new state fields (batchSellTrades, batchSellTradesLoadingStatus) and a new selector selectBatchSellTrades to expose submittable status and totalNetworkFee derived from the batch response + exchange rates; breaking: removes totalNetworkFee from selectBatchSellQuotes.

Extends runtime validation/types for the new batch response and tighter Hex typing, adds fetch utilities/tests for batch trade retrieval and malformed responses, updates snapshots/tests accordingly, and removes some now-unnecessary Hex type assertions in bridge-status-controller and transaction-pay-controller.

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