feat: readd support for the custom Data toolbox category (#87)

* chore: move data_category.js into src

* chore: format data_category.js

* chore: format constants.js

* chore: add SCALAR_VARIABLE_TYPE constant

* refactor: clean up data_category.js

src/constants.js

@@ -1,42 +1,50 @@
+/**
+ * String representing the variable type of scalar variables.
+ * This string, for use in differentiating between types of variables,
+ * indicates that the current variable is a scalar variable.
+ * @const {string}
+ */
+const SCALAR_VARIABLE_TYPE = "";
+export { SCALAR_VARIABLE_TYPE };
+
 /**
  * String representing the variable type of broadcast message blocks.
  * This string, for use in differentiating between types of variables,
  * indicates that the current variable is a broadcast message.
  * @const {string}
  */
-const BROADCAST_MESSAGE_VARIABLE_TYPE = 'broadcast_msg';
-export {BROADCAST_MESSAGE_VARIABLE_TYPE};
-
+const BROADCAST_MESSAGE_VARIABLE_TYPE = "broadcast_msg";
+export { BROADCAST_MESSAGE_VARIABLE_TYPE };
 
 /**
  * String representing the variable type of list blocks.
  * This string, for use in differentiating between types of variables,
  * indicates that the current variable is a list.
  * @const {string}
  */
-const LIST_VARIABLE_TYPE = 'list';
-export {LIST_VARIABLE_TYPE};
+const LIST_VARIABLE_TYPE = "list";
+export { LIST_VARIABLE_TYPE };
 
 /*
  * The type of all procedure definition blocks.
  * @const {string}
  */
-const PROCEDURES_DEFINITION_BLOCK_TYPE = 'procedures_definition';
-export {PROCEDURES_DEFINITION_BLOCK_TYPE};
+const PROCEDURES_DEFINITION_BLOCK_TYPE = "procedures_definition";
+export { PROCEDURES_DEFINITION_BLOCK_TYPE };
 
 /**
  * The type of all procedure prototype blocks.
  * @const {string}
  */
-const PROCEDURES_PROTOTYPE_BLOCK_TYPE = 'procedures_prototype';
-export {PROCEDURES_PROTOTYPE_BLOCK_TYPE};
+const PROCEDURES_PROTOTYPE_BLOCK_TYPE = "procedures_prototype";
+export { PROCEDURES_PROTOTYPE_BLOCK_TYPE };
 
 /**
  * The type of all procedure call blocks.
  * @const {string}
  */
-const PROCEDURES_CALL_BLOCK_TYPE = 'procedures_call';
-export {PROCEDURES_CALL_BLOCK_TYPE};
+const PROCEDURES_CALL_BLOCK_TYPE = "procedures_call";
+export { PROCEDURES_CALL_BLOCK_TYPE };
 
 const OUTPUT_SHAPE_ROUND = 2;
-export {OUTPUT_SHAPE_ROUND};
+export { OUTPUT_SHAPE_ROUND };