new whistle (#4847)

# About the pull request

This replaces the normal whistle sound (lame) with the sound of a WW1
era trench whistle (cool). It's just a sound change, nothing more
nothing less.

# Explain why it's good for the game

The sound of a trench whistle fucks hard for signaling pushes. Plus, the
old one was really lame (lame).

# Testing Photographs and Procedure
<details>
<summary>Screenshots & Videos</summary>

https://voca.ro/1i3RumMIm8qm

</details>


# Changelog
:cl:
soundadd: New whistle sound effect
/:cl: