[FEATURE]: Unclutter iCal requests

[CubicrootXYZ]

Describe the feature

Currently request to iCal resources are done after a specific interval all at once. That a. takes a lot of resources in use and b. might result in request spikes on the resource. Instead fetch the resource once when it is created and then check if it is older than X, take it and refresh it.

Describe the issue you want to resolve

Smooth load better over time.

Checklist

• This feature is not already added in the newest version
• I confirmed that there is no other issue requesting the same improvements