Allow attaching to ducklake without specifying data storage location

[cbility]

Description

Data storage location only has to be specified when creating a new ducklake, see https://ducklake.select/docs/stable/duckdb/usage/connecting. For existing ducklakes the storage location can be read from the catalog. Specifying the storage location in code also means that any change to the storage location in the catalog breaks the code.

This change removes the autogenerated data path that is inserted when a storage location is not supplied and changes the attach sql generation so that it can omit a data path if one is not supplied.

Amends existing tests so they work when storage is not specified and adds four new tests that test connecting to a ducklake without a data path for sqlite and postgres catalogs, creating a new ducklake and then attaching to it again without specifying a data path, and running dlt pipelines that create a new ducklake and then attach to it without specifying a data path.

Related Issues

• Resolves Don't require setting data_path for existing DuckLake catalogs #3796

Additional Context

• I've run tests locally and all pass excepting test_ducklake_factory_instantiation which needs S3 credentials which I don't have.
• This is my first contribution to dlt - any notes or guidance would be appreciated.
• A similar change has recently been implemented in dagster/ducklake ducklake optional DATA_PATH for local storage directories dagster-io/community-integrations#275