No changelog

This PR:

• Tidies up the tree-sitter Darklang grammar

• Adds support for DB reference (e.g. Stdlib.DB.set Test { x = "test" } "key" TestDB)

• Moves infix_operations from expressions to simple_expressions

• Improves the handling of Record and List literals:
  Before: in a Record literal, variable names had to be wrapped in parentheses to avoid being parsed incorrectly (as an apply) . Example:

    Person
      { height = (height)
        name = (name) }
  

  Now: Parentheses are no longer necessary around variable names

    Person
      { height = height
        name = name}
  

  Tree-Sitter Grammar updates to make #5321