Update state syncer to account for new features

Update state syncer (class DatabaseWidgetStateSync) to account for new
features:
- properly sync view state when switching tabs
- properly read/write view state from/to config

Update classes EntryModel and EntryView to consistenly name list/search
modes. Before, both classes defined list mode as 'group mode' and search
mode as 'entry list mode', which differed from naming in other classes
such as DatabaseWidget.

src/core/Config.cpp

@@ -138,6 +138,13 @@ void Config::init(const QString& fileName)
     m_defaults.insert("GUI/DarkTrayIcon", false);
     m_defaults.insert("GUI/MinimizeToTray", false);
     m_defaults.insert("GUI/MinimizeOnClose", false);
+    /**
+     * @author Fonic <https://github.com/fonic>
+     * Set defaults for state of 'Hide Usernames'/'Hide Passwords' settings
+     * of entry view
+     */
+    m_defaults.insert("GUI/EntryHideUsernames", false);
+    m_defaults.insert("GUI/EntryHidePasswords", true);
 }
 
 Config* Config::instance()