feat: add dialog to ask whether to chaneg instance's name

This prevents custom names from being lost when updating, by only
changing the name if the old instance name constains the old version,
so that we can update it if the user whishes to.

Signed-off-by: flow <flowlnlnln@gmail.com>

launcher/InstanceTask.h

@@ -3,6 +3,10 @@
 #include "settings/SettingsObject.h"
 #include "tasks/Task.h"
 
+/* Helpers */
+enum class InstanceNameChange { ShouldChange, ShouldKeep };
+[[nodiscard]] InstanceNameChange askForChangingInstanceName(QWidget* parent, QString old_name, QString new_name);
+
 struct InstanceName {
    public:
     InstanceName() = default;