Refactor the printing of memory usage statistics

Make the internal heap and pools memory usage statistics APIs more
similar: how the print functions are named, where they are
implemented, and which parts of them are guarded by `MEM_STATS`.
Also, adapt unit tests to the changes.

JerryScript-DCO-1.0-Signed-off-by: Akos Kiss akiss@inf.u-szeged.hu

jerry-core/mem/mem-poolman.h

@@ -63,6 +63,7 @@ typedef struct
 
 extern void mem_pools_get_stats (mem_pools_stats_t *);
 extern void mem_pools_stats_reset_peak (void);
+extern void mem_pools_stats_print (void);
 #endif /* MEM_STATS */
 
 #endif /* !MEM_POOLMAN_H */