Support for SimplyPrint cloud integration (#4525)

* Make httpserver more generic and reusable

* Add OAuthJob

* Fix issue caused by the fact that the backing widget of the `TextCtrl` is no longer `wxTextCtrl`

* Implement login and token refresh

* Implement file upload

* Try fix build error

* Support BBL printers

* Show error message if user hasn't done OAuth

* Fix typo

* Update error message

* Disable unsupported options when SimplyPrint is selected

src/slic3r/GUI/OAuthDialog.hpp

@@ -0,0 +1,34 @@
+#ifndef __OAuthDialog_HPP__
+#define __OAuthDialog_HPP__
+
+#include "GUI_Utils.hpp"
+#include "Jobs/OAuthJob.hpp"
+#include "Jobs/Worker.hpp"
+
+namespace Slic3r {
+namespace GUI {
+
+class OAuthDialog : public DPIDialog
+{
+private:
+    OAuthParams _params;
+    std::shared_ptr<OAuthResult> _result;
+
+    wxButton*               btnCancel{nullptr};
+    std::unique_ptr<Worker> m_worker;
+
+    void on_cancel(wxEvent& event);
+
+protected:
+    bool Show(bool show) override;
+    void on_dpi_changed(const wxRect& suggested_rect) override;
+
+public:
+    OAuthDialog(wxWindow* parent, OAuthParams params);
+
+    OAuthResult get_result() { return *_result; }
+};
+	
+}} // namespace Slic3r::GUI
+
+#endif