Fix and simplify st-urlhandle

[jdujava]

Improvements:

• visually simplified regexes by splitting to url and magnet parts
• properly capture "www.___" urls
• slightly more robust line concatenation, which preserves the newlines on empty lines -> before, links at the end of the lines would often become corrupted, now at least empty lines can guard the link
• fixed removing of the ending punctuation (removing "?" did not work previously)

[2084x]

is it possible to modify the regex to match the full url when quotations or non-english characters are present? eg:

https://www.youtube.com/results?search_query="test"
https://rateyourmusic.com/artist/루나