[Feature]: Info messages on Graph Page

[galee2]

Feature Proposal

Add Snackbar components to display when the user performs an action. Need to add:

• add course
• delete course
• generate prereqs
• change course taken status

Example

To see an example, try adding a course (popup exists for this). Will inform the user of the actions they perform.

Additional context

[jameszhang-a]

[bug] message doesn't disappear