Bug 1656009 - Refine the case-sensitivity checkbox behaviour
Bug 1656009 - Refine the case-sensitivity checkbox behaviour

This prevents URLs from overriding the user's saved default behaviour,
and also fixes the reported bug where the checkbox state doesn't match
the actual results.

bill-mccloskey/searchfox,bill-mccloskey/searchfox,bill-mccloskey/searchfox,bill-mccloskey/searchfox,bill-mccloskey/searchfox,bill-mccloskey/searchfox