REFACTOR: renamed ppm_flip_h and ppm_flip_v to u32_flop and u32_flip

respectively. It matches naming convention with rest of API

include/image/transformations.h

@@ -13,7 +13,7 @@
  * @retval NULL If original buffer is invalid or if new buffer fails to create
  * */
 unsigned int*
-ppm_flip_h(const unsigned int* buf, const PPM img);
+u32_flop(const unsigned int* buf, const PPM img);
 
 /**
  * @brief Flips image on Y-Axis
@@ -25,7 +25,7 @@ ppm_flip_h(const unsigned int* buf, const PPM img);
  * @retval NULL If original buffer is invalid or if new buffer fails to create
  * */
 unsigned int*
-ppm_flip_v(const unsigned int* buf, const PPM img);
+ppm_flip(const unsigned int* buf, const PPM img);
 
 /**
  * @brief Rotates image on 90 Clockwise