Graphics Preferences: Anti-aliasing + FPS (#13538)

* Expose Antialiasing velues

Expose Antialiasing multipliers.
Default to 4 as current implementation but enables the user to disable it to improve performante or increase sampling to improve quality.

* FXAA

* Improve descriptions

* Require restart when MSAA setting changes

Detect changes to the OpenGL MSAA (multisample anti-aliasing) preference when opening Preferences and prompt the user to restart the application to apply the change. Adds a constant key for the MSAA setting, stores the previous value, checks for changes (similar to the existing FXAA handling), and shows a warning dialog explaining the restart will close the current project without saving. If the user accepts, recreate_GUI is invoked to apply the MSAA change immediately.

* Revert "Require restart when MSAA setting changes"

This reverts commit dde134d346c3849598c91d025d2faed1b51c8a22.

* Menu and FPS options

* Fix FPS limiter and remove VSYNC

* Grouped FPS settings and mode up rigth fps counter

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Co-authored-by: Noisyfox <timemanager.rick@gmail.com>

src/slic3r/GUI/GLShadersManager.cpp

@@ -48,6 +48,8 @@ std::pair<bool, std::string> GLShadersManager::init()
     valid &= append_shader("flat_clip", { prefix + "flat_clip.vs", prefix + "flat_clip.fs" });
     // basic shader for textures, used to render textures
     valid &= append_shader("flat_texture", { prefix + "flat_texture.vs", prefix + "flat_texture.fs" });
+    // used to apply post-processing antialiasing in screen space
+    valid &= append_shader("fxaa", { prefix + "fxaa.vs", prefix + "fxaa.fs" });
     // used to render 3D scene background
     valid &= append_shader("background", { prefix + "background.vs", prefix + "background.fs" });
 #if SLIC3R_OPENGL_ES