Description of PR

Adds a LookupTableFile entity and LookupTableFiles collection to splunklib.client, wrapping the data/lookup-table-files/ REST endpoint.

The SDK currently has no entity class for lookup table files — users must use raw REST calls to list or inspect them. This PR follows the same Entity/Collection pattern used throughout client.py.

Changes:

• LookupTableFile(Entity) — with a download() method that retrieves CSV content via | inputlookup
• LookupTableFiles(Collection) — standard collection for listing and accessing lookup files
• Service.lookup_table_files property to access the collection
• PATH_LOOKUP_TABLE_FILES constant (data/lookup-table-files/)

Usage:

for lookup in service.lookup_table_files:
    print(lookup.name)

lf = service.lookup_table_files["my_lookup.csv"]
csv_stream = lf.download()

Note: The REST endpoint data/lookup-table-files supports listing and metadata retrieval. File upload requires eai:data to be a server-side path, which is a known REST API limitation — this PR covers the read/list surface only.

Testing the changes

Unit tests added in tests/unit/test_lookup_table_file.py (3 tests):

• Entity/Collection subclass checks
• Path constant verification

Tested with Python 3.13, Splunk Enterprise 10.4.0. Passes ruff check, ruff format, and basedpyright.

Documentation

Docstrings follow existing SDK conventions. The Service.lookup_table_files property is documented consistently with other service properties.

Dependencies and other resources

No external dependencies. Follows the same Entity/Collection pattern as Index, Application, and others in client.py.