fix: populate _split_overlap metadata for word/token units in RecursiveDocumentSplitter#11825

sjrl merged 4 commits into

deepset-ai:maindeepset-ai/haystack:mainfrom

Osamaali313:fix/recursive-splitter-word-token-overlap-metadataOsamaali313/haystack:fix/recursive-splitter-word-token-overlap-metadataCopy head branch name to clipboard