Add test_message_flags() to echo node tests.
Add test_message_flags() to echo node tests.

susansls/zulip,rht/zulip,synicalsyntax/zulip,Galexrt/zulip,aakash-cr7/zulip,kou/zulip,amanharitsh123/zulip,PhilSk/zulip,JPJPJPOPOP/zulip,rishig/zulip,vabs22/zulip,j831/zulip,mahim97/zulip,shubhamdhama/zulip,andersk/zulip,aakash-cr7/zulip,punchagan/zulip,rht/zulip,timabbott/zulip,verma-varsha/zulip,synicalsyntax/zulip,JPJPJPOPOP/zulip,aakash-cr7/zulip,tommyip/zulip,brainwane/zulip,dattatreya303/zulip,j831/zulip,souravbadami/zulip,susansls/zulip,PhilSk/zulip,jainayush975/zulip,hackerkid/zulip,brockwhittaker/zulip,eeshangarg/zulip,kou/zulip,showell/zulip,blaze225/zulip,JPJPJPOPOP/zulip,rishig/zulip,verma-varsha/zulip,brainwane/zulip,ryanbackman/zulip,vabs22/zulip,blaze225/zulip,sharmaeklavya2/zulip,jackrzhang/zulip,hackerkid/zulip,verma-varsha/zulip,blaze225/zulip,sharmaeklavya2/zulip,ryanbackman/zulip,vabs22/zulip,j831/zulip,christi3k/zulip,brockwhittaker/zulip,tommyip/zulip,brockwhittaker/zulip,christi3k/zulip,brockwhittaker/zulip,samatdav/zulip,susansls/zulip,JPJPJPOPOP/zulip,tommyip/zulip,vaidap/zulip,sharmaeklavya2/zulip,SmartPeople/zulip,jackrzhang/zulip,showell/zulip,blaze225/zulip,Galexrt/zulip,jainayush975/zulip,sonali0901/zulip,dattatreya303/zulip,andersk/zulip,zulip/zulip,mahim97/zulip,verma-varsha/zulip,dhcrzf/zulip,brainwane/zulip,aakash-cr7/zulip,dawran6/zulip,jainayush975/zulip,jrowan/zulip,shubhamdhama/zulip,ryanbackman/zulip,hackerkid/zulip,jackrzhang/zulip,ryanbackman/zulip,vabs22/zulip,PhilSk/zulip,PhilSk/zulip,jphilipsen05/zulip,dhcrzf/zulip,samatdav/zulip,christi3k/zulip,blaze225/zulip,rishig/zulip,j831/zulip,zulip/zulip,kou/zulip,dawran6/zulip,showell/zulip,rht/zulip,susansls/zulip,SmartPeople/zulip,hackerkid/zulip,synicalsyntax/zulip,shubhamdhama/zulip,dawran6/zulip,dattatreya303/zulip,andersk/zulip,rht/zulip,dhcrzf/zulip,vaidap/zulip,brockwhittaker/zulip,amanharitsh123/zulip,SmartPeople/zulip,kou/zulip,shubhamdhama/zulip,susansls/zulip,ryanbackman/zulip,sonali0901/zulip,eeshangarg/zulip,kou/zulip,rishig/zulip,dhcrzf/zulip,samatdav/zulip,kou/zulip,jphilipsen05/zulip,verma-varsha/zulip,mahim97/zulip,zulip/zulip,jackrzhang/zulip,jainayush975/zulip,dattatreya303/zulip,samatdav/zulip,jphilipsen05/zulip,jackrzhang/zulip,vaidap/zulip,christi3k/zulip,timabbott/zulip,zulip/zulip,zulip/zulip,punchagan/zulip,punchagan/zulip,souravbadami/zulip,rht/zulip,jrowan/zulip,dhcrzf/zulip,dhcrzf/zulip,aakash-cr7/zulip,verma-varsha/zulip,showell/zulip,PhilSk/zulip,PhilSk/zulip,souravbadami/zulip,rishig/zulip,mahim97/zulip,sonali0901/zulip,andersk/zulip,timabbott/zulip,souravbadami/zulip,timabbott/zulip,punchagan/zulip,jackrzhang/zulip,aakash-cr7/zulip,samatdav/zulip,vaidap/zulip,amanharitsh123/zulip,punchagan/zulip,vaidap/zulip,Galexrt/zulip,jainayush975/zulip,dawran6/zulip,blaze225/zulip,tommyip/zulip,Galexrt/zulip,mahim97/zulip,eeshangarg/zulip,j831/zulip,rishig/zulip,amanharitsh123/zulip,souravbadami/zulip,shubhamdhama/zulip,SmartPeople/zulip,jrowan/zulip,hackerkid/zulip,showell/zulip,timabbott/zulip,sonali0901/zulip,punchagan/zulip,j831/zulip,vabs22/zulip,mahim97/zulip,amanharitsh123/zulip,sharmaeklavya2/zulip,sharmaeklavya2/zulip,jphilipsen05/zulip,jrowan/zulip,christi3k/zulip,dawran6/zulip,Galexrt/zulip,andersk/zulip,rht/zulip,vabs22/zulip,brainwane/zulip,tommyip/zulip,tommyip/zulip,andersk/zulip,samatdav/zulip,christi3k/zulip,dawran6/zulip,zulip/zulip,dattatreya303/zulip,JPJPJPOPOP/zulip,showell/zulip,sonali0901/zulip,synicalsyntax/zulip,jrowan/zulip,eeshangarg/zulip,synicalsyntax/zulip,SmartPeople/zulip,eeshangarg/zulip,dhcrzf/zulip,andersk/zulip,dattatreya303/zulip,amanharitsh123/zulip,eeshangarg/zulip,ryanbackman/zulip,sonali0901/zulip,sharmaeklavya2/zulip,susansls/zulip,Galexrt/zulip,jrowan/zulip,punchagan/zulip,JPJPJPOPOP/zulip,timabbott/zulip,souravbadami/zulip,tommyip/zulip,jphilipsen05/zulip,brainwane/zulip,brainwane/zulip,kou/zulip,brainwane/zulip,SmartPeople/zulip,rishig/zulip,brockwhittaker/zulip,eeshangarg/zulip,jainayush975/zulip,rht/zulip,zulip/zulip,synicalsyntax/zulip,hackerkid/zulip,shubhamdhama/zulip,timabbott/zulip,jackrzhang/zulip,showell/zulip,vaidap/zulip,shubhamdhama/zulip,synicalsyntax/zulip,jphilipsen05/zulip,hackerkid/zulip,Galexrt/zulip