Fix case-sensitive option leaking to string/= (#40535)

Fixes #40383

If a native query parameter is set up with a string widget type that
supports a `case-sensitive` option, and that parameter is tied to a
dashboard filter that did not support that option, the option was still
leaking into the filter as an option where options were not expected.

For instance the native query parameter used `string/contains` and the
dashboard used `string/=`, the QP would try to build a filter like `[:=
field value {:case-sensitive false}]` which is an illegal filter.