Optimize explosion entity raycasts

[crosby-moe]

Overview

This pull request does two things:

1. Fixes the unused HashSet allocation redirect in block_raycast.ServerExplosionMixin that was removed during the 1.21.3 update of lithium (NEW redirects have to return a non-null object.)
2. Readds and improves upon the specialized raycast hit factory that I had added in my earlier pull request (Optimized explosion entity exposure calculations #507)

Benchmarks

~80% improvement in time spent exploding 4096 tnts.
Benchmarked using seed -3199243952349285632 (randomly chosen) and 4096 tnt (/fill ~1 ~-7 ~ ~16 ~8 ~15 tnt)

Before:
6612 ms spent in World#createExplosion (5102 ms spent in ExplosionImpl#damageEntities)

After:
3710 ms spent in World#createExplosion (1982 ms spent in ExplosionImpl#damageEntities)

[2No2Name]

The BlockGetter.clipWithInteractionOverride is replaced with VoxelShape.clip because the raycast result's direction on the block does not matter for explosions

[2No2Name]

This PR causes #630 due to removing the EntityCollisionContext, which affects raycasts, e.g. through scaffolding blocks. This is fixed in 0.15.1