test_events: Verify format of event dicts precisely.
test_events: Verify format of event dicts precisely.

This is basically just using the new check_dict_only everywhere, with
a few exceptions:
* New self.check_events_dict automatically adds the id field to avoid
  duplicating it ~80 times.
* Set log=False for many of the testing action functions to remove the
  timestamp field from their returned event dictionaries, since it's
  not needed and is the result of a deprecated log_event function.

Wasn't sure if the subscription_field list in do_test_subscribe_events
could contain optional arguments, so I left the call to check_dict on
along with a TODO.

Fixes: #1370.

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