Feature/quick filters

[chucker]

Implements #110

ToDo

• the layout as a whole needs to be shrunk.
• toolbar button to show and hide this. Do we want this per-column? Perhaps it’s easier to make the toolbar button global?
• implement text filter, probably with throttle. throttle(option: .ensureLast) looks good. https://github.com/boraseoksoon/Throttler
• need to either revamp the filtering so that it doesn’t show “filtered” for our case, or use something different altogether (it doesn’t seem to reliably apply it to existing views anyway?)
• I think autolayout broke changing the window width