e2e: do not fail to start if no irc database exist yet

Implement SASL plain authentication

e2e: Switch from coroutines to async, for python3.8

Create oragono TLS certificate automatically before each e2e run

Start oragono instead of charybdis

e2e: Switch from coroutines to async, for python3.8

e2e: fix the timeout code for expect_unordered

e2e: Add a 10s timeout for expect_stanza

Otherwise, if we expect a stanza and biboumi never sends it, we just hang
here.

Now, we display a nice error after 10 seconds, and move on to the next test,
as other failures (xpath doesn’t match) do

e2e: Implicitely include the handshake in all tests

Instead of having to write it manually everytime

Clean the __main__ file of the e2e tests

I forgot to remove some things when I moved them into functions.py

Split all the e2e tests in their own files

Some duplication is avoided, but most importantly: it’s much much cleaner,
easier to find, functions have been cleaned up (functools.partial usages are
now hidden), etc.

Remove a duplicate e2e test

Add tests for non anonymous rooms

See #3390

Expect a 210 code in the "change nick on join" e2e test

Update the e2e test to work with latest slixmpp

Update the tests to reflect the next->complete change

Add a test for outgoing /me messages that confirms issue #3382

XEP-0410: set not-in-the-room error condition to not-acceptable

XEP-0410 demands that. This changes the error condition for all
pings to the room, even those which aren’t self-pings, if the
sender is not joined.

The conditions of XEP-0410 were based on observing existing
implementations.

XEP-0410: implement server-side optimisation for self-pings

This prevents the ping from round-tripping through IRC and
possibly a random other client of the user. Please see XEP-0410
for the rationale.

Fixes #3385.

Do not send the IRC host directly as real JID of the user

Fixes #3381