[ANCM] [out of process] Write stdout to EventLog when exit code is non-zero

[shirhatti]

Epic #8833

To better diagnose pre-main errors, we should buffer whatever's written to stdout and write to EventLog in event of a non-zero exit code.

[analogrelay]

To be clear, we mean both stdout and stderr.

[analogrelay]

Let's log the first 30KB and see where that takes us for now.