[docs/nits] Fix return values based on `return_dict` and minor doc updates (#7105)
* fix returns and docs
* handle latent output_type correctly
* revert to old tensor2vid impl
* make fix-copies
* fix return in community animatediff pipes
* fix return docstring
* fix return docs
* add missing quote
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Co-authored-by: Dhruv Nair <dhruv.nair@gmail.com>