provide a link to PR creation page so user can create the pr manually

[priyesh-ave]

**Is your feature request related to a problem?
Our github org settings do not allow backport-action to create prs. It would be nice to have a link inserted into the pr comment along with the error that is currently printed.

Example link like main...release-v1 where it can create the pr with one click.

Describe the solution you'd like
As a workaround, could you update the pr comment with the actual url to create the pr. The link to create the pr (with base/target) branch populated. Could you print that in the pr comment so that as a user I can just click on the link to manually create the backport PR.

Describe alternatives you've considered
For now, my alternative is for me to create a custom step after backport-action runs to add a new comment that prepoulates the link with the base/target so i can just click it to the pr creation page.
for example main...release-v1

[korthout]

Thanks @priyesh-ave 👍 That's a good fallback for when PR creation fails.

If you're willing to contribute, I'm happy to receive a pull request for this. Note that there is a bit of a backlog right now, but I'll get to all of them eventually.