Change the frontend to respect the user's defaults even if there are parameters, unless urlversion=2 is passed.
If urlversion=2 is passed, defaults are ignored entirely.
- Instead, the de-minimis default will be "don't hide" (false or ALL, depending on type). (Others like namespace and tag already have a default of "don't hide").
If urlversion is not 2:
- No parameters: Default saved query
- Parameters: Each parameter's individual default is used unless that parameter is overridden in the URL.
Always generate urlversion=2 URLs.
See also T166906: ChangesListSpecialPage backend: Bypass defaults if urlversion=2