[FEAT]: full-text search across workspaces and threads

[socketbox]

What would you like to see?

Rather than have the user repeat a query or request because they can't recall where it is in the dozens (hundreds?) of threads they've created, why not provide them with the ability to search for it, across workspaces and threads? This functionality would include not only title (thread name) text but also the full text of chats.

I'm aware of the ability to search the current chat (using the standard Ctrl+F facility); this issue requests that the scope be expanded.

[socketbox]

One potential way of going about this: https://www.librechat.ai/docs/configuration/meilisearch

In docker compose, this would look something akin to this: https://github.com/danny-avila/LibreChat/blob/6c9a468b8e4b08d844351a2a448c7933d78559df/docker-compose.yml#L37