Ensure only defined annotations are allowed

At this time, users are not given any linting warnings when undefined annotations are used, including misspellings.

Additional Notes:

• An example: someone might use toggle_warnings instead of toggle_warning.
• It has been noted that removing the ability to comment between annotations (see https://github.com/openedx/code-annotations/issues/89) would make this simpler to implement.
• Linting might be implemented here: https://github.com/openedx/edx-lint/blob/7573005f89df7f78142a2af86673206e8b43c4d5/edx_lint/pylint/annotations_check.py#L291

从 edx_lint/pylint/annotations_check.py 第 291 行附近开始，以了解现有的 linting 入口点。查看 issue #89 中关于注解之间注释的讨论，然后将完成定义为：当注解名称未定义或拼写错误时发出警告，例如使用 toggle_warnings 而不是 toggle_warning。