Add swap hands toggle functions (#20381)

quantum/action.h

@@ -84,6 +84,18 @@ typedef uint32_t swap_state_row_t;
 #        error "MATRIX_COLS: invalid value"
 #    endif
 
+/**
+ * @brief Enable swap hands
+ */
+void swap_hands_on(void);
+/**
+ * @brief Disable swap hands
+ */
+void swap_hands_off(void);
+/**
+ * @brief Toggle swap hands enable state
+ */
+void swap_hands_toggle(void);
 /**
  * @brief Get the swap hands enable state
  *
@@ -91,6 +103,7 @@ typedef uint32_t swap_state_row_t;
  * @return false
  */
 bool is_swap_hands_on(void);
+
 void process_hand_swap(keyevent_t *record);
 #endif