Resolve "Filters do not work properly with new requests"

What does this mr do?

It will fix the filters for new requests whenever they get updated automatically.

Actions taken to fix bug

Change the filter for adding new requests. It was a check if either the assigned was null or if the assigned was contained in the selected assigned, but with new requests the assigned was always null such that it would always go through the filter. Now it is changed to check if it either contains it or if all are selected.

Does this MR meet the acceptance criteria?

• I have added a changelog entry to reflect the significant changes I made and the bug I fixed.
• A test was created to test the bug.
• I have updated the documentation accordingly.
• I adhere to the style guide.

Closes #300 (closed)