Fixed the issue with "expression" - Moved "ranking_windowed_function" and "aggregate_windowed_function" into   "function_call", and placed them before "scalar_function_name ..."
Fixed the issue with "expression"
- Moved "ranking_windowed_function" and "aggregate_windowed_function" into
  "function_call", and placed them before "scalar_function_name ..."

  Now, aggregate and ranking function are part of the "function_call" and have
  higher precedence over user defined scalar functions.

  Previously, built-in functions like AVG, MAX, etc., were not being recognized
  as aggregate_windowed_function if they are not followed by an OVER clause.
  They both got recognized as user defined "scalar_function_name" because
  the "function_call" has higher precedence in "expression"

- Removed labels on "ranking_windowed_function" and "aggregate_windowed_function"

- Removed "over_clause" from "expression" since it's already included in
  "ranking_windowed_function" and "aggregate_windowed_function"

antlr/grammars-v4,antlr/grammars-v4,antlr/grammars-v4,antlr/grammars-v4,antlr/grammars-v4,antlr/grammars-v4,antlr/grammars-v4,antlr/grammars-v4,antlr/grammars-v4,antlr/grammars-v4,antlr/grammars-v4,antlr/grammars-v4