Fix S3Path copy to Local: name collision of file / dir

[ap--]

Close #528

TODO:

• investigate why azurite is failing on ubuntu runners
• Add test to base tests for all object-store like filesystems
• Should warn by default if a name collision occurs instead of silently copying either file or dir

Future TODO:

• add isfile/isdir collision tests to s3fs, gcsfs, adlfs
• Revisit how warning on collisions can be done in an unintrusive way