remove some allow && do some refactor

[asukaminato0721]

This pull request includes several changes to improve the functionality and code quality of the del-geo-core module. The key changes involve adding new methods, refactoring existing methods for better readability and performance, and removing unnecessary code.

New Methods Added:

• del-geo-core/src/mat3_col_major.rs: Added transform_homogeneous method to the Mat3ColMajor trait and its implementation. [1] [2]

Refactoring for Readability and Performance:

• del-geo-core/src/obb3.rs: Refactored test_nearest_to_point3 function to use method chaining for better readability.
• del-geo-core/src/polynomial_root.rs: Replaced num_traits::clamp with the clamp method for better performance and readability.
• del-geo-core/src/view_projection.rs: Simplified matrix multiplication in the Perspective struct's implementation.
• del-geo-core/src/view_rotation.rs: Refactored Trackball struct's methods to use method chaining and instance methods for better readability. [1] [2]

Code Cleanup:

• del-geo-core/src/spherical_harmonics.rs: Removed unnecessary clippy lint allowances.

Dependency Management:

• del-geo-core/src/view_projection.rs: Added Mat4ColMajor import.
• del-geo-core/src/view_rotation.rs: Added Quaternion import.

[nobuyuki83]

Looks very good !👍 Thank you @asukaminato0721