Allow failed function executions to only mark some rows as failed

Currently if a function throws an exception it will fail the entire batch of rows sent, retrying them again in 60sec. This isn't great if a it was a single row that caused the exception - since it means that user functions need to be resilient to possibly retries and may end up with "good" rows being ignored if even a single bad row causes some exception.

It would be good to look into providing a way for functions to tell the trigger binding what rows it was able to successfully process and then only mark the ones that aren't in that list as needing to be retried.