Describe the bug
Not sure if intentional, but gravel blocks don't give excavation XP when broken.

Expected behavior
Like other such base level blocks, they probably should give XP.

To Reproduce
Steps to reproduce the behavior:

1. Start a new world
2. Break a gravel block by hand
3. Get no XP

Versions:

• Minecraft: 1.19.2
• Loader: Forge-43.2.4
• PMMO: 1.19-3.0.2

Additional context
Made a PR for this: #246

Also added some missing mushroom files in another PR: #248

And a bunch more someone reported: #249