This PR adds support for enabling or disabling the notification sound in `esx_notify`.
A new variable `NotificationSoundEnabled` (default: true) controls whether a sound should be played when a notification is shown.
```lua
---@type boolean Whether the notification sound should be played
local NotificationSoundEnabled = true
```
- [x] My commit messages and PR title follow the [Conventional Commits](https://www.conventionalcommits.org/en/v1.0.0/) standard.
- [ ] My changes have been tested locally and function as expected.
- [x] My PR does not introduce any breaking changes.
- [x] I have provided a clear explanation of what my PR does, including the reasoning behind the changes and any relevant context.
alexistb2904