Add a belt-and-suspenders feature, limit the amount of
memory and cpu possible when unlucky or simply misconfigured.
The worst case limit is roughly 400kB * 10,000 = 4GB, regardless
of usage pattern.
Before this change, sheer volume of broadcasts, mismatches in
standardness rules, or simply fee mismatches may result in unbounded
growth of memory usage. As the feature may be expanded in
the future, explicit bounds helps reasoning going forward.
Github-Pull: #35406
Rebased-From: 5aea3d0373