Trigger: Add Sound "Coin"

Summary:
One preview is better than a thousand of words:

{F270656}

This Sound is probably universally recognized thanks to
videogames like Super Mario® or other popular platforms; but
this specific Coin Sound is not proprietary: it's released
with a Free as in Freedom of Speach license: Creative Commons 0.

As if that were not enough, this Coin sound, instead of
potentially creating frustration like many others - it positively
stimulates part of the human cerebral cortex involved in making
humans more addicted to Phorge. To be precise, this Coin sound is
particularly suitable to be associated with Trigger actions
such as:

- Mark as Resolved
- Move on to the next Milestone
- etc.

But the only limitation here, as usual in Phorge, is
your imagination.

Insert a Coin and have fun with Phorge.

Complete sound credits:

https://freesound.org/people/Jocabundus/sounds/678385/

2023, Jocabundus, Creative Commons Zero (public domain dedication)

This change also introduces a Credits page in Diviner to mentions this
kind of things. Future contributions in that page are encouraged.

Insert a Coin. Play again with Phorge.

Ref T15178
Ref T15248

Test Plan:
- Create a Project with a Workboard
- Create a Column
- Column > Gear > New Trigger...
- Action > Play Sound > "Coin"
- Create a Task on the Backlog column, and drop it on your new Column
- Turn on audio, have fun!

Reviewers: O1 Blessed Committers, Cigaryno, avivey, aklapper

Reviewed By: O1 Blessed Committers, Cigaryno, avivey, aklapper

Subscribers: avivey, aklapper, chris, speck, tobiaswiese, Matthew, Cigaryno

Maniphest Tasks: T15178, T15248

Differential Revision: https://we.phorge.it/D25079