This PR Adds sounds to opening and closing barrels. The sounds are properly attributed in the 'attribution.txt' file. They are published under Creative Commons 0 (CC0) and the source for them is [here](https://freesound.org/people/quantumriver/sounds/552153/)
Reviewed-on: https://git.minetest.land/MineClone2/MineClone2/pulls/3670
Reviewed-by: ancientmarinerdev <ancientmariner_dev@proton.me>
Co-authored-by: SmokeyDope <smokey@tilde.team>
Co-committed-by: SmokeyDope <smokey@tilde.team>
SmokeyDope
AFCMS
MysticTempest