support `/` path format with `databricks fs`

[copdips]

Hello,

When using databricks fs subcommand, we must add dbfs:/ as path prefix, but to easy the operation (we often copy path starting from / from web or doc), could you please also add a wrapper to auto convenrt / to dbfs:/ ?

$ databricks fs ls /FileStore
Error: The path /FileStore must start with "dbfs:/"