E2E testing against IRCD/Homeserver

[Half-Shot]

This work contains the initial parts required to construct full e2e tests. This uses a similar technique to the matrix-node-irc library of providing a specalised test class for creating all the dependencies needed for testing.

TODO:

• [x] matrix-node-irc release
• [x] CI support
• [x] actual tests

Outstanding bugs:

• [x] Inspircd won't let us connect when running via GH actions, possibly IP issues?
  • Fixed by running inspircd "on the host"
• Tests sit around forever after exiting, need to find what's holding the process open.
  • Bug in matrix-appservice-bridge, fixed in upstream but for now we just force exit. https://github.com/matrix-org/matrix-appservice-bridge/pull/439

[Neustradamus]

@Half-Shot: Good job for IRC, can you merge for XMPP? :)