feat!: display the parameters as knobs in a grid

Also removed the negbandpass & neghighpass parameters
and replaced them with bandpass & highpass set to -1, to
fit the switches better to the GUI.

Closes #51, closes #173

tracker/model_test.go

@@ -239,7 +239,7 @@ func (s *modelFuzzState) IterateTable(name string, table tracker.Table, yield fu
 		table.Fill(seed % 16)
 	})
 	yield(name+".Add", func(p string, t *testing.T) {
-		table.Add(seed % 16)
+		table.Add((seed>>1)%16, seed%2 == 0)
 	})
 }