Add RecommendedFee and broadcasting methods to SingleAddressWallet

[ChrisSchinnerl]

No description provided.

[Copilot]

Pull Request Overview

This PR adds broadcasting methods and a fee recommendation mechanism to the SingleAddressWallet. It updates the wallet creation signature to require a syncer, introduces new methods in the ChainManager interface, and updates related tests and RPC handling to use these changes.

• Updated wallet creation in tests to include a MockSyncer.
• Added BroadcastTransactionSet, BroadcastV2TransactionSet, and RecommendedFee methods to SingleAddressWallet.
• Updated ChainManager interface and associated tests and RPC handlers to utilize the new fee recommendation feature.

Reviewed Changes

Copilot reviewed 7 out of 7 changed files in this pull request and generated 2 comments.

Show a summary per file

File	Description
wallet/wallet_test.go	Updated test wallet creation to pass &testutil.MockSyncer{} to the updated constructor.
wallet/wallet.go	Added new broadcasting methods and fee recommendation logic; updated NewSingleAddressWallet signature.
testutil/testutil.go	Added the MockSyncer implementation for test usage.
rhp/v4/rpc_test.go	Updated wallet instantiation and added tests for the RecommendedFee method.
rhp/v4/rpc.go	Replaced direct fee retrieval from TxPool with signer.RecommendedFee in contract-related methods.
.changeset/*.md	Added change log notes for the new broadcast methods and fee recommendation changes.