Support URL and URL301 for porkbun

[fkrauthan]

Is your feature request related to a problem? Please describe.
It looks like even thought porkbun has URL redirect support it requires a custom PORKBUN_URLFWD call to configure. When using URL I get the error that url is not supported.

Describe the solution you'd like
It would be great if the more "standardized" URL and URL301 could be mapped to the porkbun url forward system.

Describe alternatives you've considered
Keep using the prokbun specific PORKBUN_URLFWD. But this makes the definition slightly less portable (e.g. switching from porkbun to namecheap or vice versa).

[cafferata]

Ping @imlonghao, the maintainer of the Porkbun provider.