Implement `wf:q_post` and `wf:q_get` or something like that.

Something to simplify retrieving values, where `wf:q` pulls from POST and GET, being able to specify the source explicit without dropping into `simple_bridge` to do it.  This would also warrant all the variations as well: mq_post, mq_get, qs_post, qs_get, etc.

Alternatively, `wf_post:q()`, and `wf_get:q()` - I kind of like that more.