Add button to rescan BT devices

Otherwise the divecomputer has to be in pairing mode
at app start time.

Unfortunately, this leaves less space for the progress message.
My time/qml knowledge does not suffice to move that to the next line
(when moving that out of the RowLayout it overlaps with
the buttons).

Signed-off-by: Robert C. Helling <helling@atdotde.de>

mobile-widgets/qml/DownloadFromDiveComputer.qml

@@ -215,6 +215,14 @@ Kirigami.Page {
 					manager.appendTextToLog("exit DCDownload screen")
 				}
 			}
+			SsrfButton {
+				id:rescanbutton
+				text: qsTr("Rescan")
+				onClicked: {
+					manager.btRescan()
+				}
+			}
+
 			Controls.Label {
 				Layout.maximumWidth: parent.width - download.width - quitbutton.width
 				text: divesDownloaded ? qsTr(" Downloaded dives") :