This change implements async log retrievals via feeding logs in channels, instead of returning slices. This is a first step to implement #15063.  

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Signed-off-by: jsvisa <delweng@gmail.com>
Co-authored-by: Sina Mahmoodi <itz.s1na@gmail.com>
Co-authored-by: Martin Holst Swende <martin@swende.se>
Co-authored-by: Sina Mahmoodi <1591639+s1na@users.noreply.github.com>