QML UIL: fix more problems with members moving from manager to prefs

That change clearly would have benefited from better code review.
This is a superset of a change proposed by Jan Iversen.

Closes #1406

Signed-off-by: Dirk Hohndel <dirk@hohndel.org>

mobile-widgets/qml/CloudCredentials.qml

@@ -117,7 +117,7 @@ Item {
 				id: cancelpin
 				text: qsTr("Cancel")
 				onClicked: {
-					manager.cancelCredentialsPinSetup()
+					prefs.cancelCredentialsPinSetup()
 					rootItem.returnTopPage()
 				}
 			}

mobile-widgets/qml/Settings.qml

@@ -52,7 +52,7 @@ Kirigami.ScrollablePage {
 				Layout.alignment: Qt.AlignRight
 				text: qsTr("Change")
 				onClicked: {
-					manager.cancelCredentialsPinSetup()
+					prefs.cancelCredentialsPinSetup()
 					rootItem.returnTopPage()
 				}
 			}

mobile-widgets/qml/StartPage.qml

@@ -52,7 +52,7 @@ 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(manager.cloudUserName)
+				"at our user forum \(https://subsurface-divelog.org/user-forum/\).<br/><br/>").arg(prefs.cloudUserName)
 			wrapMode: Text.WordWrap
 		}
 		Item { width: Kirigami.Units.gridUnit; height: 3 * Kirigami.Units.gridUnit}