test_narrow: Add test for search operation using email.
test_narrow: Add test for search operation using email.

Fixes #3074.

(Note the main issue was actually fixed by
2f09866364b2bf991ef611af27a9b3d9642f0eda); this just adds a test.

andersk/zulip,jrowan/zulip,timabbott/zulip,jackrzhang/zulip,rishig/zulip,shubhamdhama/zulip,tommyip/zulip,synicalsyntax/zulip,christi3k/zulip,synicalsyntax/zulip,jrowan/zulip,shubhamdhama/zulip,jphilipsen05/zulip,hackerkid/zulip,Galexrt/zulip,vabs22/zulip,Galexrt/zulip,dhcrzf/zulip,vaidap/zulip,vabs22/zulip,christi3k/zulip,zulip/zulip,hackerkid/zulip,showell/zulip,shubhamdhama/zulip,ryanbackman/zulip,j831/zulip,punchagan/zulip,brainwane/zulip,jrowan/zulip,ryanbackman/zulip,zulip/zulip,eeshangarg/zulip,andersk/zulip,rht/zulip,synicalsyntax/zulip,vaidap/zulip,Galexrt/zulip,brockwhittaker/zulip,j831/zulip,synicalsyntax/zulip,timabbott/zulip,kou/zulip,jphilipsen05/zulip,rishig/zulip,eeshangarg/zulip,dhcrzf/zulip,dhcrzf/zulip,synicalsyntax/zulip,shubhamdhama/zulip,ryanbackman/zulip,jackrzhang/zulip,kou/zulip,brockwhittaker/zulip,kou/zulip,rht/zulip,mahim97/zulip,rht/zulip,showell/zulip,vaidap/zulip,vabs22/zulip,kou/zulip,showell/zulip,brainwane/zulip,timabbott/zulip,vabs22/zulip,zulip/zulip,timabbott/zulip,kou/zulip,andersk/zulip,timabbott/zulip,zulip/zulip,jphilipsen05/zulip,zulip/zulip,rht/zulip,rht/zulip,punchagan/zulip,ryanbackman/zulip,j831/zulip,zulip/zulip,eeshangarg/zulip,andersk/zulip,jackrzhang/zulip,brockwhittaker/zulip,vaidap/zulip,kou/zulip,jackrzhang/zulip,brockwhittaker/zulip,j831/zulip,brainwane/zulip,christi3k/zulip,synicalsyntax/zulip,verma-varsha/zulip,brockwhittaker/zulip,eeshangarg/zulip,tommyip/zulip,shubhamdhama/zulip,jphilipsen05/zulip,hackerkid/zulip,rishig/zulip,amanharitsh123/zulip,verma-varsha/zulip,punchagan/zulip,showell/zulip,hackerkid/zulip,ryanbackman/zulip,vaidap/zulip,dhcrzf/zulip,shubhamdhama/zulip,brainwane/zulip,verma-varsha/zulip,showell/zulip,j831/zulip,j831/zulip,mahim97/zulip,dhcrzf/zulip,tommyip/zulip,jphilipsen05/zulip,timabbott/zulip,hackerkid/zulip,tommyip/zulip,christi3k/zulip,punchagan/zulip,mahim97/zulip,andersk/zulip,vabs22/zulip,amanharitsh123/zulip,tommyip/zulip,jackrzhang/zulip,eeshangarg/zulip,jackrzhang/zulip,shubhamdhama/zulip,vaidap/zulip,amanharitsh123/zulip,rishig/zulip,amanharitsh123/zulip,dhcrzf/zulip,jrowan/zulip,eeshangarg/zulip,verma-varsha/zulip,timabbott/zulip,brainwane/zulip,hackerkid/zulip,rishig/zulip,punchagan/zulip,showell/zulip,Galexrt/zulip,dhcrzf/zulip,mahim97/zulip,synicalsyntax/zulip,punchagan/zulip,amanharitsh123/zulip,Galexrt/zulip,verma-varsha/zulip,tommyip/zulip,jackrzhang/zulip,tommyip/zulip,ryanbackman/zulip,Galexrt/zulip,eeshangarg/zulip,brainwane/zulip,zulip/zulip,vabs22/zulip,jphilipsen05/zulip,Galexrt/zulip,showell/zulip,jrowan/zulip,rht/zulip,andersk/zulip,andersk/zulip,hackerkid/zulip,brainwane/zulip,verma-varsha/zulip,christi3k/zulip,amanharitsh123/zulip,rishig/zulip,mahim97/zulip,christi3k/zulip,brockwhittaker/zulip,jrowan/zulip,rht/zulip,mahim97/zulip,kou/zulip,rishig/zulip,punchagan/zulip