Coin control: clear selected coins after send and clear form

[johnny9]

Gap

QML clears recipients after send or clear-form actions, but selected coin-control inputs remain in m_coin_control. Qt widgets unselect all coin-control inputs after successful send and clear.

Work

Clear selected coins when the send form is cleared and after successful send. Make the visible coin-control state and backend coin-control state stay synchronized.

Code References

• qml/pages/main.qml:194
• qml/models/sendrecipientslistmodel.cpp:177
• bitcoin/src/qt/sendcoinsdialog.cpp:553
• bitcoin/src/qt/sendcoinsdialog.cpp:562