Compatibility with `copernicusmarine v2`

[VeckoTheGecko]

Note that I just got an email from Copernicus Marine Service that they are about to update their copernicusmarine to v2.0.0, which has some breaking changes: https://help.marine.copernicus.eu/en/articles/9978784-what-s-new-in-the-pre-release-of-version-2-0-0-of-the-copernicus-marine-toolbox.

So it might be good to already implement the new API in virtualship fetch

Originally posted by @erikvansebille in #83 (comment)

---

Once copernicusmarine 2 is out on pypi (https://pypi.org/project/copernicusmarine/), we should update our code to use the latest version. Pinning <2 for now 3b5edc6

[erikvansebille]

Just received note that v2.0.0 of the copernicusmarine toolbox has been released: https://help.marine.copernicus.eu/en/articles/9978784-what-s-new-in-version-2-0-0-of-the-copernicus-marine-toolbox