raise error if token count exceeds 1024 instead of attempting to re-chunk

[khaledsulayman]

In the sdg_hub code where this came from, there was a call to chunk_document() that would be made if the token count of a particular chunk exceeded 1024.

The chunk_document function uses the recursive text splitter to split chunks to certain token size thresholds, but realistically should not be needed anymore given our use of the hybrid chunker. This PR raises a more explicit error in the case that we do exceed 1024.

[alimaredia]

Could we get the first X and last X tokens in the chunk printed out as well as all chunks that are too big into a list and all printed out at once. This way a users know where they need to trim down their chunks before moving forward.

It would look something like:

Chunk Size Errors:
Chunk "foo bar baz ... biz baz bar."  exceeds max token count of 1024.
Chunk "foo2 bar2 baz2 ... biz2 baz2 bar2."  exceeds max token count of 1024.
....