[Bug]: Validate RSS Feeds before adding it to the subscription

[monksy]

What happened?

When you add a URL that is not a valid RSS feed. (I.e. https://www.javaoffheap.com/rss-feeds) Airsonic doesn't stop you from proceeding. It'll try to add a null feed to the subscription.

Throw an error if the feed cannot be reached.

Steps to reproduce

1. Add "feed" https://www.javaoffheap.com/rss-feeds
2. See null podcast

Should be doing: Reporting an error and stopping you from proceeding

Version

11.1.5-SNAPSHOT (Edge)

Version Detail

No response

Operating System

docker/linux

Java Version

docker jvm version

Database

PostgreSQL 14.x

DB Detail

No response

Configuration paramter

none

Proxy Server

No response

client detail

No response

language

English

Relevant log output

No response