Explosive sand

### Added
- Added a new configuration command: `/sandexplosion set <value>` to change explosion power dynamically.
- Supported explosion range is from `3.0` (standard layout) up to `20.0` (massive cataclysmic blast!).
- Added a new reset command: `/sandexplosion reset` to quickly restore the default explosion power back to normal.

Command Syntax Update:

- `/sandexplosion on` - Enables the feature.
- `/sandexplosion off` - Disables the feature.
- `/sandexplosion status` - Checks current mod status.
- `/sandexplosion set <3.0-20.0>` - Customizes the blast radius.
- `/sandexplosion reset` - Resets configuration to default.