Add scope for function parameter used inside function

Got send here from 'vscode-python' https://github.com/microsoft/vscode-python/issues/11594

def function(param1):
    x = 1
    return param1 * x

Both x and param1 are variables used inside the function, but param1 is a given parameter.

In the function def line param1 has a special scope but not when used inside the function.
I'd like to have it have a special textmate scope too so I can color it and see, when I use a parameter and when a 'normal' variable.

The left side is what I want (from PyCharm) and the right side is as currently is.

该 issue 没有列出实现文件或测试；首先定位 MagicPython 的 Python 语法高亮规则，并将函数示例中的参数定义与其在函数内部的使用进行比较。完成的标准是：参数引用获得与普通局部变量不同的 TextMate scope，并覆盖所示示例。