mobile UI/login: replace use of cloudUserName

Replace prefs.cloudUserName with PrefCloudStorage.cloud_storage_email in QML

Replace QMLPrefs.....cloudUserName with PrefCloudStorage::cloud_storage_email in C++

Signed-off-by: Jan Iversen <jani@apache.org>
Signed-off-by: Dirk Hohndel <dirk@hohndel.org>

mobile-widgets/qml/CloudCredentials.qml

@@ -58,7 +58,7 @@ Item {
 
 		Controls.TextField {
 			id: login
-			text: prefs.cloudUserName
+			text: PrefCloudStorage.cloud_storage_email
 			visible: !prefs.showPin
 			Layout.fillWidth: true
 			inputMethodHints: Qt.ImhEmailCharactersOnly |
@@ -101,7 +101,7 @@ Item {
 			visible: prefs.showPin
 			SsrfButton {
 				id: registerpin
-				text: qsTr("Register") 
+				text: qsTr("Register")
 				onClicked: {
 					saveCredentials()
 				}

mobile-widgets/qml/StartPage.qml

@@ -50,7 +50,7 @@ Kirigami.ScrollablePage {
 				"If you do not receive an email from us within 15 minutes, please check " +
 				"the correct spelling of your email address and your spam box first.<br/><br/>" +
 				"In case of any problems regarding cloud account setup, please contact us " +
-				"at our user forum \(https://subsurface-divelog.org/user-forum/\).<br/><br/>").arg(prefs.cloudUserName)
+				"at our user forum \(https://subsurface-divelog.org/user-forum/\).<br/><br/>").arg(PrefCloudStorage.cloud_storage_email)
 			wrapMode: Text.WordWrap
 		}
 		Item { width: Kirigami.Units.gridUnit; height: 3 * Kirigami.Units.gridUnit}

mobile-widgets/qml/main.qml

@@ -225,7 +225,7 @@ Kirigami.ApplicationWindow {
 						visible: text.length > 0
 						level: 3
 						color: "white"
-						text: prefs.cloudUserName
+						text: PrefCloudStorage.cloud_storage_email
 						wrapMode: Text.NoWrap
 						elide: Text.ElideRight
 						font.weight: Font.Normal