UI Enhancements (#1308)

* Center the account text on the balance page

* Modify dashboard button spacing

* Change default theme to Dark theme

* Remove legacyTheme and modify theme order

* Add condition for Monero.com wallet default theme

* Add locale for new themes

* Add new themes

* Update padding

* Fixes

* Update settings_store.dart

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Co-authored-by: Omar Hatem <omarh.ismail1@gmail.com>

lib/core/backup_service.dart

@@ -464,8 +464,6 @@ class BackupService {
       PreferencesKey.disableSellKey: _sharedPreferences.getBool(PreferencesKey.disableSellKey),
       PreferencesKey.defaultBuyProvider:
           _sharedPreferences.getInt(PreferencesKey.defaultBuyProvider),
-      PreferencesKey.isDarkThemeLegacy:
-          _sharedPreferences.getBool(PreferencesKey.isDarkThemeLegacy),
       PreferencesKey.currentPinLength: _sharedPreferences.getInt(PreferencesKey.currentPinLength),
       PreferencesKey.currentTransactionPriorityKeyLegacy:
           _sharedPreferences.getInt(PreferencesKey.currentTransactionPriorityKeyLegacy),