Adding QoL for `batch_size` arg (like others enabled everywhere).
Author: Narsil
Pull request: yes

# What does this PR do?

Adds a `pipeline(.. batch_size=16)` argument. 
Previously this was `__call__` only argument: `pipe = pipeline(....); pipe(..., batch_size=16)`.

This PR made both supported (like all other pipeline arguments).

Some linked issues: https://github.com/huggingface/transformers/issues/14327
https://github.com/huggingface/transformers/issues/14333#issuecomment-973007453

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Fixes # (issue)


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Comments:
Gentle reminder to fill the description of PRs pretty please, before merging @Narsil :-)

@sgugger Oups, sorry !  Done. :D