Advanced filtering criteria with fields

[MrTimbones]

The table view has a very simple filter that looks for the entered text across the entire row. We may need something more sophisticated in the future once we have a sizeable number of submissions. Something like wot eBay and Amazon have.

For instance, being able to select a specific field and a range of values, e.g. heat pumps with output greater than 10 kW.
Multiple fields can combined to refine the list of systems shown.

[kamilfb]

Hi. Here as a proposed enhancement to support additional operators in the query string:
#69, and a side panel to add/edit/view the filter: #70. Still work in progress, but would be great to get your thoughts on this.