0x0 block hash issue leading to possible fork of the node

[sophoah]

Describe the bug

A block hash of 0x0 may occur under certain corner cases of the node operation.

For the case of a leader, it may lead to the node being forked and not able to participate into consensus.

Team has been able to reproduce the issue in localnet but depends a lot on resource usage

To Reproduce
Using a CPU/Memory stress tool

Steps to reproduce the behavior:

1. run localnet
2. use the stress tool

Expected behavior
no 0x0 hash should ever be used during consensus

Additional context
Add any other context about the problem here.