Add support for storing filters in dashboard entries

closes #102 This PR adds support for storing filters and changing them in the dashboard entry form. It adds 2 new tables for storing filters and a component for choosing them. I wanted to make it so that the Downshift opens again if the tag is not fully finished, but I could not find a way to do this. I am open to any suggestions regarding my code, and I haven't written any tests yet.. That's why it's a draft PR.