Fix Apprise notification logo (Discord webhook logo, etc)

[kristianvld]

The current logo used for notifications through Apprise use the default Apprise logo, instead of the Huntarr.io logo.

The images below are examples from Discord. On Discord, webhooks can either send no logo (use the configured logo at the Discord server) or send a logo (override the logo set in the Discord server). Since a logo is sent from Apprise of the default Apprise logo, it is impossible to override this on a server level.

[RaunoT]

In Huntarr Apprise URL's config: discord://<your-webhook-info>?avatar_url=https://cdn.jsdelivr.net/gh/homarr-labs/dashboard-icons/png/huntarr.png

[spider1163]

This image could be enabled by default