Add more advanced error handling

[XInTheDark]

It is crucial that the bot knows how to handle unexpected errors.

Timeline:

• In 25caf75a900113fe88d9eb5b842655fe39594c3e, basic error handling was mostly complete.
• Then, I realised that when hosting on Replit, many repls share the same IP address; hence it is common to be rate limited by discord.
  • In 36b4c0e3edc019245443ea8083e6f3c075c523ed, a small bypass was added.
  • In 3c516e8d9742dcac457e95581c9499e0993df234, the (mostly) complete bypass was added.

However, there are many other use scenarios and errors that are not handled properly as of now. It is important that we fix these errors, making the bot more stable, before adding new functionality.

Our goal for now is simple: to ensure that the bot can run automatically and completely on its own, without any human intervention or maintenance.

[XInTheDark]

This aspect seems to be mostly complete; closing as completed for now.