feat: filter content + move view all button

[ElijahFeldman7]

The PR adds a feature for filtering submissions by:

• Language
• Problem
• Verdict
  The menu is collapsible, starting off as such:

After clicking on filters, the menu comes up:

These contain collapsible fields, that can be multiselected:

Clear filters removes all filters. The options are only available if they are present, so if you only have python submissions you can only pick python or all.

Clicking apply filters at the top closes the menu and applies the filters via creating a csv and parsing it into lists to apply __in filters.

I also moved the view all button from

to

imo this placing looks a lot better and text isnt on two lines.

Let me know if you have any questions/ optimizations.