* Drop support for delegating email validation
Delegating email validation to an IS is insecure (since it allows the owner of
the IS to do a password reset on your HS), and has long been deprecated. It
will now cause a config error at startup.
* Update unit test which checks for email verification
Give it an `email` config instead of a threepid delegate
* Remove unused method `requestEmailToken`
* Simplify config handling for email verification
Rather than an enum and a boolean, all we need here is a single bool, which
says whether we are or are not doing email verification.
* update docs
* changelog
* upgrade.md: fix typo
* update version number
this will be in 1.64, not 1.63
* update version number
this one too
Part of the Tchap Synapse mainlining.
This allows modules to implement extra logic to figure out whether a given 3PID can be added to the local homeserver. In the Tchap use case, this will allow a Synapse module to interface with the custom endpoint /internal_info.
This avoids the overhead of searching through the various
configuration classes by directly referencing the class that
the attributes are in.
It also improves type hints since mypy can now resolve the
types of the configuration variables.
