Add missing imports for Python bindings

[CGodiksen]

This PR fixes a small bug in the Python bindings that was caused by the convenience functions not being imported in the __init__.py file from operations.py. With this PR it should now be possible to use both modelardb.Operations.open_local() and modelardb.open_local().

Note that most of the changes are from Clippy issues. The relevant change that fixes the bug is in crates/modelardb_embedded/bindings/python/modelardb/__init__.py.

[Copilot]

Pull Request Overview

This PR fixes Python bindings imports to enable direct access to convenience functions and addresses various Clippy code style issues throughout the Rust codebase.

• Adds missing imports in Python bindings __init__.py to expose convenience functions like open_local()
• Refactors nested if-let statements to use let-chains pattern for better readability
• Replaces slice creation patterns with slice::from_ref() for single element slices

Reviewed Changes

Copilot reviewed 7 out of 7 changed files in this pull request and generated no comments.

Show a summary per file

File	Description
crates/modelardb_embedded/bindings/python/modelardb/init.py	Adds missing convenience function imports to fix Python binding access
crates/modelardb_storage/src/query/normal_table.rs	Adds explicit lifetime parameter to Cow type
crates/modelardb_storage/src/query/grid_exec.rs	Uses slice::from_ref() for single element slice creation
crates/modelardb_storage/src/parser.rs	Refactors nested if-let statements to let-chains pattern
crates/modelardb_storage/src/optimizer/model_simple_aggregates.rs	Simplifies nested conditionals using let-chains
crates/modelardb_server/tests/integration_test.rs	Replaces single-element array references with slice::from_ref()
crates/modelardb_bulkloader/src/main.rs	Combines conditional check with error handling using let-chains

Comments suppressed due to low confidence (1)

crates/modelardb_server/tests/integration_test.rs:20

• The std::iter import is being removed but it's still used elsewhere in the file. Verify that iter is imported in the combined import on line 27 to avoid compilation errors.

use std::ops::Range;