Prepare for event system

Moved stuff around.
Create an entry point for RSE.
Created base for events module

Signed-off-by: Piotr Krygier <piotrkrygier@everyonecancode@xyz>

graphics/rse_graphics.h

@@ -1,10 +1,9 @@
 #ifndef RSE_GRAPHICS_H
 #define RSE_GRAPHICS_H
 
+#include "src/graphics_context.h"
 #include "utilities/commons.h"
 
-struct rse_graphics_context_t;
-
 /**
  * @brief Initializes graphics backend. This has to be called before any new mesh, texture or any other object is
  * added
@@ -12,20 +11,20 @@ struct rse_graphics_context_t;
  * @param context Graphics context handle. Must be NULL!
  * @return rse_err_t RSE_ERROR_NO_ERROR on success
  */
-rse_err_t rse_graphics_init(struct rse_graphics_context_t** context);
+rse_err_t rse_graphics_init(struct graphics_context_t* context);
 
 /**
  * @brief Runs graphics engine. This has to be called after all objects are added to the scene
  *
  * @return rse_err_t RSE_ERROR_NO_ERROR on success
  */
-int rse_graphics_run(void* arg);
+rse_err_t rse_graphics_main_loop(struct graphics_context_t* context);
 
 
 /**
  * @brief Custom function for testing engine. TODO: Remove it whe releasing
  *
  */
-rse_err_t rse_graphics_test_function(struct rse_graphics_context_t* context);
+rse_err_t rse_graphics_test_function(struct graphics_context_t* context);
 
 #endif /* RSE_GRAPHICS_H */