Stream characters in for tool calls to allow rendering partial input.


https://github.com/zed-industries/zed/assets/836375/0f023a4b-9c46-4449-ae69-8b6bcab41673

Release Notes:

- N/A

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Co-authored-by: Max Brunsfeld <maxbrunsfeld@gmail.com>
Co-authored-by: Marshall <marshall@zed.dev>
Co-authored-by: Max <max@zed.dev>