Chunking for uploads via Bedrock

[djriversq]

https://docs.aws.amazon.com/bedrock/latest/userguide/conversation-inference-call.html#conversation-inference-call-request

The Bedrock Converse API has a limit of 4.5MB per file, up to 5 files (3.75MBx20 for images), and this isn't ideal for larger documents which can't be uploaded as a result, however it would seem feasible to add some sort of chunking of uploads so a large file could be fed into LibreChat, split up into 2 or more parts via the RAG API, then uploaded to Bedrock.