Refactor/improve user friendly errors

[Vinnie-Singleton-NN]

Summary

Added new code to convert error messages into user friendly (non-technical) messages. This improves usability in situations where a non-technical user may not understand error messages. For example, translating an "Overloaded" error to "The AI service is currently experiencing high demand. Please wait a moment and try again." This is done through pattern matching and mapping to relevant messages.

The stack trace information is preserved for users with more technical knowledge.

Change Type

• New feature (non-breaking change which adds functionality)

Testing

The easiest way to test is to generate errors. I would suggest the following:

1. Send a message to a model that is too large to fit in the context window.
2. Send messages to a model at a frequency that exceeds the model quota (it is useful to write separate code to message a provider asynchronously, saturate the quota, and then send a message in LibreChat).
3. Attempt to send a message to a deprecated model.

Checklist

• My code adheres to this project's style guidelines
• I have performed a self-review of my own code

[plasticlobster]

@danny-avila Can we get some feedback on this PR?