Fixed bug regarding manga volumes in discord rich presence

[Gamesmes90]

I found a bug regarding the rich presence.

I was testing the extension with Komga and found out that if the manga has "volume" or "volumes" tag, the rich presence will display "Chapter: 0 of X".

Checking for the volumes fixes the issue. I also called the "UI_Volume" directly.

[henrik9999]

There are pages that have volume and chapter at the same time I would prefer that it shows the chapter number or maybe both instead then

[Gamesmes90]

There are pages that have volume and chapter at the same time I would prefer that it shows the chapter number or maybe both instead then

Sorry, I didn't know that. I can try adding both. What pages can show both?

[Gamesmes90]

Now it shows both volume and chapter number.

I changed "of" with a slash to save space when it shows both.

[lolamtisch]

I think the chapter should be in front, as it is the more important metric. Would be annoying if it would cut of.

[Gamesmes90]

Done.

[lolamtisch]

I cleaned up the code.
I removed the untranslated "of".
And the totalchap/volume is only shown if there is one as the ? wasnt that helpfull in the presence