[Feature] refactor podcast RSS

[mrhackcz]

Hi,

I'm using podgrab in docker with an HTTP port exposed directly. But Im not able to make it work in Apple podcasts.

If I add a podcast via RSS URL, I see episodes but can't play them. I have a suspicion, that it is caused by "non-valid" RSS generated by podgrab. Apple recommends validating podcasts URL with https://podba.se/validate .

Can you please check it ?
Thank you

[SamTV12345]

If you'd like to you can checkout https://github.com/SamTV12345/PodFetch . I was able to add it to iTunes and already validated the generated XML with the W3C RSS tool.