remove useStrictQuery, and use strict for both options

[AbdelrahmanHafez]

on strictQuery docs it mentions that

For backwards compatibility, the strict option does not apply to the filter parameter for queries.

6.0 is a good opportunity to get rid of it, and use strict option for it by default.

[jonchurch]

I'm curious about the context around this change, is there an issue where this was discussed?

[vkarpov15]

@jonchurch TBH we should have had more discussion about this. We thought it would be good to remove an extra option, but missed that removing the option had some undesirable consequences.