Our old group SMTP SSL option was a checkbox,
but this was not ideal because there are actually
3 different ways SSL can be used when sending
SMTP:
* None
* SSL/TLS
* STARTTLS
We got around this before with specific overrides
for Gmail, but it's not flexible enough and now people
want to use other providers. It's best to be clear,
though it is a technical detail. We provide a way
to test the SMTP settings before saving them so there
should be little chance of messing this up.
This commit also converts GroupEmailSettings to a glimmer
component.
