Engine Refactor #2: Setup Query Parser Test (#85)

* organize queries, setup test for parser

* fix syntax

* fix tests

* update test

Author: HazelYuAhiru

core/query_parser.py

@@ -0,0 +1,23 @@
+from core.ast.node import QueryNode
+
+class QueryParser:
+
+    def parse(self, query: str) -> QueryNode:
+        # Implement parsing logic using self.rules
+        pass
+
+        # [1] Call mo_sql_parser
+        # str ->  Any (JSON)
+
+        # [2] Our new code
+        # Any (JSON) -> AST (QueryNode)
+
+    def format(self, query: QueryNode) -> str:
+        # Implement formatting logic to convert AST back to SQL string
+        pass
+
+        # [1] Our new code
+        # AST (QueryNode) ->  JSON
+
+        # [2] Call mo_sql_format
+        # Any (JSON) -> str