loading can fw needs UI ack for no change

when loading a can fw to a device a check is done for if the firmware is already on the device. If this check does find it is already there then there is no UI feedback for the user unless they happen to have the terminal window visible. It needs some sort of UI element to show that the firmwares match.

No file or test is named. Start by tracing the CAN firmware-loading check and the existing terminal feedback, then identify the Mission Planner UI entry point for the load operation. Done means the UI visibly tells the user when the device already has the matching firmware.

Written by the indexing model from the issue text.