require fsspec>=2022.1.0

[ap--]

This PR closes #141 by introducing a minimum version requirement for fsspec>=2022.1.0. I went as far back as reasonable before larger parts of the test suite started failing.

Some notes:

• I'm xfailing the few tests that require slightly newer versions of fsspec for specific implementations. (I.e. some mkdir stuff for gcsfs<2022.7.1, or a webdav test that needs fsspec>=2022.5.0, etc...)

TODO:

• add CI job testing against fsspec==2022.1.0
• decide if we should:
  • fix the fs specific behavior for these xfailed tests 🚫
  • add min version requirements per implementation 🚫
  • just document them (my preferred option right now) ✔️