rendering: Simplify Cairo context usage, remove unneeded calls.

Moved Cairo context usage to Rust, and rearranged ctx setup (position) to happen in one place.

Removed render calls that were overwritten on each draw call anyway.

eek/eek-renderer.h

@@ -25,7 +25,6 @@
 #include <pango/pangocairo.h>
 
 #include "eek-types.h"
-#include "src/layout.h"
 
 G_BEGIN_DECLS
 
@@ -36,9 +35,6 @@ struct _EekRendererClass
 {
     GObjectClass parent_class;
 
-    void             (* render_keyboard)    (EekRenderer *self,
-                                             cairo_t     *cr);
-
     cairo_surface_t *(* get_icon_surface)   (EekRenderer *self,
                                              const gchar *icon_name,
                                              gint         size,