Add Parquet Export Format to `lino pull` Command

To enhance performance and reduce storage requirements, this sub-task involves adding support for exporting data in Parquet format as part of the `lino pull` command. (#309)

**Tasks:**
- Integrate a library for Parquet serialization within the `lino` tool.
- Implement logic to export the pulled data in Parquet format.
- Add a `--format parquet` option to the `lino pull` command.
- Ensure compatibility with existing flags and options in `lino pull`.
- Write unit and integration tests to validate Parquet export functionality.
- Update the documentation to include usage examples for Parquet format.

**Acceptance Criteria:**
- The `lino pull` command exports data in Parquet format.
- The Parquet export is compatible with relevant `lino pull` flags and options.
- Documentation is updated with examples of Parquet format usage.