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.

tests/end_to_end/scenarios/client_error.py

@@ -0,0 +1,16 @@
+from scenarios import *
+
+scenario = (
+    scenarios.simple_channel_join.scenario,
+    # Second resource, same channel
+    send_stanza("<presence from='{jid_one}/{resource_two}' to='#foo%{irc_server_one}/{nick_one}' />"),
+    expect_stanza("/presence[@to='{jid_one}/{resource_two}'][@from='#foo%{irc_server_one}/{nick_one}']/muc_user:x/muc_user:item[@affiliation='admin'][@role='moderator']",
+                  "/presence/muc_user:x/muc_user:status[@code='110']"),
+    expect_stanza("/message[@from='#foo%{irc_server_one}'][@type='groupchat'][@to='{jid_one}/{resource_two}']/subject[not(text())]"),
+
+    # Now the first resource has an error
+    send_stanza("<message from='{jid_one}/{resource_one}' to='#foo%%{irc_server_one}/{nick_one}' type='error'><error type='cancel'><recipient-unavailable xmlns='urn:ietf:params:xml:ns:xmpp-stanzas'/></error></message>"),
+    # Receive a leave only to the leaving resource
+    expect_stanza("/presence[@type='unavailable'][@from='#foo%{irc_server_one}/{nick_one}'][@to='{jid_one}/{resource_one}']/muc_user:x/muc_user:status[@code='110']",
+                  "/presence/status[text()='Biboumi note: 1 resources are still in this channel.']"),
+)