`signrawtransactionwithwallet` does not take enough information to sign

If you try to call `signrawtransactionwithwallet` on an unconfirmed input, you need to provide the input's information, including the amount (for segwit) and asset (for Taproot). But the RPC does not take the asset. So you cannot sign Taproot outputs with this RPC.

該 issue 將 signrawtransactionwithwallet 指定為進入點；請定位其 RPC 實作以及現有的、用於對未確認輸入進行簽署的測試。確定應如何為 Taproot 提供缺少的資產資訊，然後確認 RPC 能夠從未確認輸入對 Taproot 輸出進行簽署，且不會破壞現有呼叫。

由索引模型根據 Issue 內容生成。