Add Missing Tests for AICosineSimilarityDistanceTest

[pankaj-bind]

Added test for

• Checks that the Cosine Similarity between zero vectors returns 1.0 or is handled gracefully.
• Checks that the Cosine Similarity between identical vectors is 1.0.
• Checks that the Cosine Similarity between orthogonal vectors is 0.0.
• Checks that an error is raised for collections of different lengths.
• Checks that an error is raised for non-numeric inputs.

From AICosineSimilarityDistance.class.st I have removed previous method and added new.
Why?
The previous method lacks zero-vector handling (causing division-by-zero errors), uses non-standard array operations (*), and doesn’t validate inputs. The new method is more robust, portable, and includes input validation (length and numeric checks) and zero-vector handling, making it the better choice for reliable cosine similarity computation.

[pankaj-bind]

Hey @jordanmontt, please review this PR