Dead entities are not affected by knockback

Clone of MCPE-19222
The dead entities are not affected by knockback. This means the dead entities are not pushed away and knocked off when they're dying.

How to Reproduce
1. Build a single block tower.
2. Spawn a mob.
3. Give yourself a strength effect. (to kill entities in a single hit)
/effect @s strength 10000 6 true
4. Kill it.

Expected Result
The mob is knocked off/pushed away off the platform.

Observed Result
The mob is not knocked off/pushed away, without any knockback.