Support step parameter in slice_assign method

[antimora]

Feature Request

Currently, the slice_assign method in the repository does not support a step parameter, limiting its flexibility for advanced slicing operations. Adding support for the step parameter would allow users to perform more complex slice assignments similar to standard Python and NumPy slicing.

Proposed Solution:

• Update the slice_assign method to accept and handle a step parameter.
• Ensure proper validation and error handling for different step values (positive, negative, zero).
• Add tests to verify correct behavior with various step values.
• Update documentation to reflect the new parameter and provide usage examples.