Replace sequences of whitespace (including newlines) with either a single space or remove them entirely (according to param spaced).

  compress_lines(<<QUERY)
    SELECT name
    FROM users
  QUERY => "SELECT name FROM users"

@param [String] string

  The input string.

@param [TrueClass, FalseClass] spaced (default=true)

  Determines whether returned string has whitespace collapsed or removed.

@return [String] The input string with whitespace (including newlines) replaced.

@api semipublic