notifications: Use call_consume_in_tests for email sending.
notifications: Use call_consume_in_tests for email sending.

This adds a bit of test coverage with really no downside.

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