Recursive function to construct query

[habiba-m]

• recurse_fields(): a recursive function that constructs a query using the necessary fields and subfields
• For each field in the fields dictionary, the method:
  • retrieves the field's path in the graph using field_map
  • checks if the field has subfields (i.e., if it's a complex type). If so, it recursively calls itself with the subfields and the updated indent level.
  • If the field is a scalar type, it simply adds the field name to the query string.
• For each subfield, the method:
  • Recursively calls itself with the subfield's path and the updated indent level.
  • Adds the subfield's name and value to the query string, indented according to the indent level.
• Base Case: when the value is a scalar type
• More test cases added