Revive project

[yutotakano]

Work on finalising the existing rewrite (called "2.4.0-dev") and making it compile for recent discord-haskell and GHC versions.

• Make sure the library compiles on latest stable GHC versions and discord-haskell versions
• Fix any compilation errors that have creeped in for the existing protocol version (v4)
• Make example programs work with v4
• Update all Haddock where necessary
• Update README and ChangeLog entries
• Release the v4-compatible rewritten package on Hackage

Work on updating the library to work with changes from the last 3 years of Discord Voice protocol updates.

• Update voice protocol to v8 (Update voice protocol to v8 #62)
  • Review and implement major changes to the protocol: new types, new messages, etc
  • Perform ongoing analysis and update this list as necessary
  • Review and implement any changes required for the DAVE end-to-end encryption protocol (or postpone if the existing xsalsa20_poly1305 works)
  • XSalsa20_Poly1305 is deprecated and already unsupported, move to AES GCM
  • Make example programs work with v8
• Release the v8-compatible package on Hackage

Generally:

• Note down the pain points of the library in terms of both end user use cases and development, which might help in thinking of a better library API in the future