Move filter options into the buttons for each column

[jamesaoverton]

Having all the various filter options at the top is OK for now, but eventually I'd like it to work more like filtering in Excel or Google Sheets.

We currently have a button for each column marked with a down arrow icon. Clicking on these reveals Ascending and Descending sort buttons. I'd like the filtering options to be included here:

1. the operator + value filter
2. the error level filter

There should still be a global filter for error level, as currently implemented.