Added a SettingsDialog with a "Server" tab to configure the server settings.

dialogs/settingsdialog.h

@@ -0,0 +1,23 @@
+#ifndef SETTINGSDIALOG_H
+#define SETTINGSDIALOG_H
+
+#include "abstractdialog.h"
+
+class QLineEdit;
+
+class SettingsDialog : public AbstractDialog {
+  Q_OBJECT
+ public:
+  SettingsDialog(QWidget* parent = nullptr);
+
+  void createContent() override;
+  void fillContent(const QVariantMap& settings);
+  QVariantMap getSettings() const;
+
+ private:
+  QLineEdit* m_urlEdit      = nullptr;
+  QLineEdit* m_emailEdit    = nullptr;
+  QLineEdit* m_passwordEdit = nullptr;
+};
+
+#endif  // SETTINGSDIALOG_H