Invalid reuse of variables in CREATE clause

[MuhammadTahaNaveed]

Describe the bug
Age is allowing invalid reuse of variables in CREATE clause.

How are you accessing AGE (Command line, driver, etc.)?

• terminal

What is the command that caused the error?

SELECT * from cypher('my_graph_name', $$
  CREATE p=(p)
$$) as (a agtype);

This command should error out saying that p is already declared but it passes.

 result 
--------
(0 rows)

SELECT * from cypher('my_graph_name', $$
  CREATE p=(p) RETURN p
$$) as (a agtype);

ERROR:  column reference "p" is ambiguous
LINE 1: ...ELECT * from cypher('new4', $$CREATE p=(p) RETURN p$$) as (r...

Expected behavior
Should have failed with error saying p already declared

Environment (please complete the following information):

• latest

Additional context
Need to add proper checks for valid variable reuse.