Feat: backend refactoring

[Antosik]

Done:

• Backend
  • Core was rewritten to async/await (19a4e75)
• Misc
  • ESLint - eslint-config-nodebb (78a47c0)
  • Logging - include plugin name in error message (79e3178)
  • Errors translations (c85405f)

P.S. Reviewers, please double check everything ^^"

[Antosik]

TBD next (in another PRs):

• Move to the client-side hooks (for supported events)

[julianlam]

Move to the client-side hooks (for supported events)

The way I have been doing it is... if I want to convert a plugin $(window).on(event) listener and the corresponding core $(window).trigger(event) is not using the hooks module, I will convert the one in core. No need to wait for us, just open a PR against core to convert :smile:

Core will continue to make the $(window).trigger call for backwards compatibility.