Feat: flashing icon to indicate async classes

[Bennables]

Summary

There was no way to tell if you had asynchronous classes on antalmanac.

Test Plan

Add an async class and see if the UI changes

Issues

Closes #1181

[vicksey]

Hey @Bennables, I tested this and it works as intended, but it currently never turns off once triggered.
We also talked as a team about how this might not be the right long term solution for notifying users about async courses being added. For now, users can still rely on the MUI snackbar confirmation when an async course is added, so we're going to hold off on merging this. I’ll start looking into cleaner alternatives to display added async courses.

[KevinWu098]

Closing as not planned and/or superceded by alternate implementation