qml wizard: "confirm seed" screen to normalize whitespaces

fixes https://github.com/spesmilo/electrum/issues/8442

electrum/gui/qml/components/wizard/WCConfirmSeed.qml

@@ -13,7 +13,7 @@ WizardComponent {
     valid: false
 
     function checkValid() {
-        var seedvalid = confirm.text == wizard_data['seed']
+        var seedvalid = wizard.wiz.isMatchingSeed(wizard_data['seed'], confirm.text)
         var customwordsvalid =  customwordstext.text == wizard_data['seed_extra_words']
         valid = seedvalid && (wizard_data['seed_extend'] ? customwordsvalid : true)
     }

electrum/gui/qml/qewizard.py

@@ -4,8 +4,10 @@ from PyQt5.QtCore import pyqtProperty, pyqtSignal, pyqtSlot, QObject
 from PyQt5.QtQml import QQmlApplicationEngine
 
 from electrum.logging import get_logger
+from electrum import mnemonic
 from electrum.wizard import NewWalletWizard, ServerConnectWizard
 
+
 class QEAbstractWizard(QObject):
     _logger = get_logger(__name__)
 
@@ -93,6 +95,10 @@ class QENewWalletWizard(NewWalletWizard, QEAbstractWizard):
         data = js_data.toVariant()
         return self.has_heterogeneous_masterkeys(data)
 
+    @pyqtSlot(str, str, result=bool)
+    def isMatchingSeed(self, seed, seed_again):
+        return mnemonic.is_matching_seed(seed=seed, seed_again=seed_again)
+
     @pyqtSlot('QJSValue', bool, str)
     def createStorage(self, js_data, single_password_enabled, single_password):
         self._logger.info('Creating wallet from wizard data')