This is part of our general process of replacing emails, which are not
static with time, with user_ids when referring to users in the API.
We still keep the `email` reference option, since it can be useful for
linking third-party applications to Zulip on an intranet that might
have a user's corporate email handy and not want to do the extra round
trip to lookup the user.
The name of the parameter, user_id_or_email, was chosen to to make it
clear that the default/preferred option is user_id.
Fixes#14304.
api docs filenames are basically the operationId of their endpoint
in zulip.yaml with `_` replaced by `-`. But some operationIds have
changed, so change the affected filenames. Make changes in other
files accordingly.
Tushar912
orientor