Bug 317101

When editing/adding a filter rule, the tab order for the input fields is weird.
I focus the Criteria field, enter eg. To, press tab, and the next focussed field is the "Plus" button to add another rule. Make the tab order logical.

Reproducible: Always

Steps to Reproduce:
1. Go to Settings → Filters
2. Create new filter or choose existing one
3. Focus any of the criteria input boxes
4. Press tab button (several times)
Actual Results:  
Tab order: Criteria → Plus icon of current row → Search term input → Operator combobox → Next row criteria
and after the last row's operator combobox the focus moves to the "Clear all" button of the filter action(!)

Expected Results:  
Tab order: Criteria → Operator combobox → Search term input → Plus icon of current row → Next row's criteria