events: Use property_types framework to deduplicate code.
events: Use property_types framework to deduplicate code.

This cuts another block of code that we needed to add for every new user
setting.

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