Implemented sort by answer and rewrote core part of code to allow for multi filters

[silasm01]

Added new filter to only show assignments that has been seen by teacher. Whether or not grade has been set
Also rewrote code to where each filter can take multiple parameters:
[["5", "Afventer"],["7","Lærer"]]
Also rewrote to fix weird behavior where multiple filters override each other.
Now you can use multiple filter at once without any problems.

[Reikimann]

Thx for the commit! :D Also please explain the numbers in this: [["5", "Afventer"],["7","Lærer"]].

[Reikimann]

@silasm01 have you tested the code? Its not working. I've tried going back to the other commits you've done, but they aren't working either. Could you please look at it?

The code looked fine, but it isn't working.

[silasm01]

This works fine for Firefox. Although i just checked on chrome and after converting to map() it seems to be broken on chrome. It throws an error:
Uncaught TypeError: Cannot read properties of null (reading 'map')
With a stack trace going to line 194.

[silasm01]

This seemed to be caused by chrome trying to access localStorageItems before they have been loaded as it tries to preload the extension. This has been fixed by checking if localStorageItems is Null before using them. It seems that it works for both Chrome and Firefox now. Found fix at: https://stackoverflow.com/questions/70264846/%C3%97-typeerror-cannot-read-properties-of-null-reading-map.

[Aech27]

Okay, otherwise i will be able to look for a fix in chromium based browsers