WISH: Provide link from problems.md to package's CRAN check page

[HenrikBengtsson]

Currently, revdepcheck problems.md reports provide:

# spNetwork

<details>

* Version: 0.2.1
* GitHub: https://github.com/JeremyGelb/spNetwork
* Source code: https://github.com/cran/spNetwork
* Date/Publication: 2021-10-30 09:50:02 UTC
* Number of recursive dependencies: 147

Run `revdep_details(, "spNetwork")` for more info

</details>

When there's an unexpected error, I always find myself going to the CRAN check page to see if that error show up there as well, e.g. in the above example, I navigate to https://cran.r-project.org/web/checks/check_results_spNetwork.html, which takes a few cut'n'paste and clicks to get to.

I'd like to suggest adding a link for this as:

* GitHub: https://github.com/JeremyGelb/spNetwork
* Source code: https://github.com/cran/spNetwork
* CRAN results: https://cloud.r-project.org/web/checks/check_results_spNetwork.html