feat: add reset for individual filters

[A-Behairi]

this introduces a reset functionality for every filter type in eox-itemfilter. When a user chooses to assign values to the filter, a reset icon appears next to the filter title and allows to reset the properties of that specific filter.

[silvester-pari]

Thank you, works great! I chose a simpler icon (X) for now, I feel like this is easier on the eyes. I also tried to harmonize it with the "reset all" button.

I think we can merge this now, we can still keep looking for better icons in the future.