Dbfs HF (#1214)
* remerge
* import supported extensions
* no circular imports
* local import
* typo
* testing
* test
* test
* more test
* rm . from ext
* clean up and pre commit
* imports and boolean typo
* revert one exception, use backend over startwith, and set path using parse_uri
* move import to local
* debug
* typo
* debug
* more debug
* debug
* clean up
* back to debug
* typo
* add slash
* move slash to verify_uc_path
* moved back
* debug
* more debug
* clean up
* pyright
* generic error messaging
* move NotFound up
* dbfs directory check
* precommit
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Co-authored-by: Daniel King <43149077+dakinggg@users.noreply.github.com>
Co-authored-by: v-chen_data <v-chen_data@example.com>
