heap: Refactor heap regions/capabilities out of FreeRTOS

Remove tagged heap API, rename caps_xxx to heap_caps_xxx

Also includes additional heap_caps_xxx inspection functions.

components/esp32/include/esp_system.h

@@ -95,6 +95,13 @@ uint32_t esp_get_free_heap_size(void);
   */
 uint32_t system_get_free_heap_size(void)  __attribute__ ((deprecated));
 
+/**
+  * @brief Get the minimum heap that has ever been available
+  *
+  * @return Minimum free heap ever available
+  */
+uint32_t esp_get_minimum_free_heap_size( void );
+
 /**
  * @brief  Get one random 32-bit word from hardware RNG
  *