Users can hide their public profile and presence information by checking
“Hide my public profile and presence features” on the
`u/{username}/preferences/interface` page. In that case, we also don't
want to return user status from the server.
This work has been started in https://github.com/discourse/discourse/pull/23946.
The current PR fixes all the remaining places in Core.
Note that the actual fix is quite simple – a5802f484d.
But we had a fair amount of duplication in the code responsible for
the user status serialization, so I had to dry that up first. The refactoring
as well as adding some additional tests is the main part of this PR.
* Add timezone to user_options table
* Also migrate existing timezone values from UserCustomField,
which is where the discourse-calendar plugin is storing them
* Allow user to change their core timezone from Profile
* Auto guess & set timezone on login & invite accept & signup
* Serialize user_options.timezone for group members. this is so discourse-group-timezones can access the core user timezone, as it is being removed in discourse-calendar.
* Annotate user_option with timezone
* Validate timezone values
This reduces chances of errors where consumers of strings mutate inputs
and reduces memory usage of the app.
Test suite passes now, but there may be some stuff left, so we will run
a few sites on a branch prior to merging
