[feature_request] update sensor for grades

[rine77]

Is your feature request related to a problem? Please describe.
nope

Describe the solution you'd like
I would like to have a separate sensor with new grades per day. If there is a new grade (or more, some teachers add multiple grades per session) I want the sensor to display all changes.

Describe alternatives you've considered
Alternatively it could be implemented with Home Assistant automations, but I believe it's one of the benefits of the integration: to keep track of the grades of your beloved students