Add support for pathslicing for the seaweedfs backend

this actually requires quite some refactoring in the seaweedfs backend, mostly to support the (somewhat useless) list_content() method.

changed milestone to %SWH Mirror at ENEA [Roadmap - Preserve]

added activity::Implementation label

changed title from Add support for pathslicing in seaweedfs backend to Add support for pathslicing for the seaweedfs backend

added 5 commits

• 85a03558...3afa1ec8 - 3 commits from branch swh/devel:master
• 8332711c - Make the limit argument of ObjStorage.list_content() method optional
• 74a51569 - Add support for pathslicing in seaweedfs backend

Compare with previous version

resolved all threads

Updated the MR with a significant rework of this MR.

Got the list_content and __iter__ methods working, simplified a few methods. Added a few tests, and add a pair of test scenarios with an objstorage filled with more objects than the DEFAULT_LIMIT value...

DEFAULT_LIMIT and setup.py stuff should be in their own commits, but ok

approved this merge request

merged