This is a fix for a user's problem. They have custom domain set, a
custom cert in the `stacks/ssl` folder, but because a different team
operates a reverse-proxy, they aren't sure which _host_ is actually used
by the reverse proxy. And the way we bind to port 443 requires that that
puzzle be solved, for very little extra value.
This change makes it so that we accept any incoming TLS connections, if
a custom domain is set, which should be much more convenient.
[Slack
Thread](https://theappsmith.slack.com/archives/C0341RERY4R/p1705700120412079).
Already deployed on users' system, and they've confirmed its working.
Another attempt at #29550, which was reverted. Fallback is not happening
if cert provisioning fails _despite_ having the correct header. But with
the changes in this PR, since we'll listen on `:80`, fallback _will_
happen when cert provisioning fails due to incorrect domain
configuration.
We're also adding [Hurl](https://hurl.dev) based tests. They're not run
in any CI yet. That'll come in soon.
