frontend_tests: Replace optparse with argparse.
frontend_tests: Replace optparse with argparse.

Tweaked by tabbott to fix the command name being reported properly.

showell/zulip,jackrzhang/zulip,jackrzhang/zulip,synicalsyntax/zulip,zulip/zulip,timabbott/zulip,eeshangarg/zulip,eeshangarg/zulip,rishig/zulip,punchagan/zulip,amanharitsh123/zulip,hackerkid/zulip,showell/zulip,Galexrt/zulip,rht/zulip,hackerkid/zulip,shubhamdhama/zulip,brainwane/zulip,brainwane/zulip,shubhamdhama/zulip,rishig/zulip,punchagan/zulip,showell/zulip,synicalsyntax/zulip,tommyip/zulip,jackrzhang/zulip,brainwane/zulip,rht/zulip,synicalsyntax/zulip,kou/zulip,Galexrt/zulip,zulip/zulip,punchagan/zulip,punchagan/zulip,andersk/zulip,timabbott/zulip,Galexrt/zulip,jackrzhang/zulip,eeshangarg/zulip,rht/zulip,andersk/zulip,andersk/zulip,synicalsyntax/zulip,Galexrt/zulip,kou/zulip,brainwane/zulip,rht/zulip,zulip/zulip,dhcrzf/zulip,rht/zulip,dhcrzf/zulip,punchagan/zulip,mahim97/zulip,shubhamdhama/zulip,timabbott/zulip,kou/zulip,eeshangarg/zulip,hackerkid/zulip,tommyip/zulip,mahim97/zulip,shubhamdhama/zulip,andersk/zulip,Galexrt/zulip,punchagan/zulip,zulip/zulip,kou/zulip,hackerkid/zulip,showell/zulip,brockwhittaker/zulip,dhcrzf/zulip,rht/zulip,Galexrt/zulip,showell/zulip,brockwhittaker/zulip,timabbott/zulip,rht/zulip,tommyip/zulip,dhcrzf/zulip,timabbott/zulip,tommyip/zulip,dhcrzf/zulip,showell/zulip,jackrzhang/zulip,kou/zulip,andersk/zulip,shubhamdhama/zulip,amanharitsh123/zulip,shubhamdhama/zulip,dhcrzf/zulip,brockwhittaker/zulip,zulip/zulip,rishig/zulip,Galexrt/zulip,brockwhittaker/zulip,hackerkid/zulip,synicalsyntax/zulip,amanharitsh123/zulip,amanharitsh123/zulip,rishig/zulip,shubhamdhama/zulip,jackrzhang/zulip,zulip/zulip,synicalsyntax/zulip,andersk/zulip,hackerkid/zulip,brainwane/zulip,mahim97/zulip,dhcrzf/zulip,tommyip/zulip,amanharitsh123/zulip,rishig/zulip,eeshangarg/zulip,timabbott/zulip,punchagan/zulip,jackrzhang/zulip,kou/zulip,brockwhittaker/zulip,mahim97/zulip,brainwane/zulip,showell/zulip,eeshangarg/zulip,mahim97/zulip,rishig/zulip,amanharitsh123/zulip,zulip/zulip,eeshangarg/zulip,rishig/zulip,mahim97/zulip,kou/zulip,tommyip/zulip,tommyip/zulip,synicalsyntax/zulip,brainwane/zulip,brockwhittaker/zulip,andersk/zulip,hackerkid/zulip,timabbott/zulip