Add Entity Sneaking and Sprinting for other clients.

Status

• Ready
• Development
• Hold

Description

Added 2 new systems that send a EntityMetadata packet, that tells clients that a certain entity is sneaking or sprinting.
Added pose Enum to EntityMetadata, also changed Const name to better fit.
Added a send_entity_metadata to client.

Related issues

Checklist

• Ran cargo fmt, cargo clippy --all-targets, cargo build --release and cargo test and fixed any generated errors!
• Removed unnecessary commented out code
• Used specific traces (if you trace actions please specify the cause i.e. the player)

Note: if you locally don't get any errors, but GitHub Actions fails (especially at clippy) you might want to check your rust toolchain version. You can then feel free to fix these warnings/errors in your PR.