IDLE colorizer - Properly highlight function/class names

Bug report

Bug description:

def 4545(): # “4545” highlighted correctly
               # because identifiers cannot
               # start with digits

being highlighted:

How it should render

How it renders instead

class MID·DOT(): 

How it should render

How it renders instead

“·” (U+00B7) is a XID_Continue character

CPython versions tested on:

3.15, 3.14, 3.13, 3.9, 3.10, 3.11, 3.12

Operating systems tested on:

Windows

Linked PRs

• gh-137612

在开始之前，检查两个示例中描述的 IDLE 着色器行为，并查看链接的 PR gh-137612。确认 issue 中的函数名和类名在列出的 CPython 版本上均按预期截图所示进行渲染，包括 U+00B7 情况。