Add test for extractQuery().
Add test for extractQuery().

decaffeinate-examples/vimium,willsALMANJ/vimium,smblott-github/vimium,gdh1995/vimium,decaffeinate-examples/vimium,decaffeinate-examples/vimium,poacher2k/vimium,smblott-github/vimium,philc/vimium,poacher2k/vimium,gdh1995/vimium,willsALMANJ/vimium,poacher2k/vimium,smblott-github/vimium,mrmr1993/vimium,philc/vimium,willsALMANJ/vimium,mrmr1993/vimium,mrmr1993/vimium,philc/vimium,gdh1995/vimium