[dataquery] Clear operator when the filter field changes

[HenriRabalais]

Description

When you change the field on a filter, the Criteria operator dropdown keeps showing the operator you picked for the previous field. You can end up with an operator that is not valid for the new field, or have to re-click the same option when it is still valid.

FilterableSelectGroup wraps react-select without passing a value prop, so react-select keeps the selected option in its own internal state. The field onChange already calls setOp(null) and setValue(''), which clears the parent state, but the dropdown itself never remounts so it keeps displaying the old operator.

The field dropdown right above it already handles this by keying on the category. This does the same thing for the operator dropdown, keying it on the field name so it remounts when the field changes.

Changes

• Added key={fieldname} to the operator FilterableSelectGroup in the Add criteria modal, so it resets to the "Select an operator" placeholder whenever the field changes.

Testing Instructions

1. Go to the Data Query Tool (Beta) and click Add Filters, then Add Condition.
2. Select the "Candidate Demographics" category and the "Date of Birth" field.
3. Under Criteria, select the < operator. A date input appears next to it.
4. Now change the field to "Candidate's biological sex".
5. The operator should reset to "Select an operator" and the date input should disappear. Before this change the dropdown still showed <, which is not a valid operator for an enum field.

Related Issues

Resolves #10781