i.smap: add test file

[jayneel-shah18]

This PR introduces a comprehensive test suite for the i.smap GRASS GIS module, validating its functionality. The suite ensures the robustness of classification algorithms.

Key Updates in this PR

• Synthetic Data Generation: Procedurally generates test data using mathematical expressions.
• Basic Classification Test: Validates correct classification into distinct classes.
• Goodness Map Test: Checks the accuracy of the goodness-of-fit map.
• Maximum Likelihood Estimation Test: Ensures correct application of the -m flag.
• Block Size Consistency Test: Evaluates the stability of results across different block sizes.

Test Case Descriptions

1. Basic Classification Test
   • Verifies that the classification using i.smap produces the expected number of distinct classes.
2. Goodness Map Generation
   • Assesses the correctness of the goodness map by comparing statistical properties against reference values.
3. Maximum Likelihood Estimation Validation
   • Ensures proper application of the -m flag and evaluates the classification accuracy using r.kappa.
4. Block Size Impact
   • Compares outputs across different block sizes to validate result consistency.

Performance

• Windows: 2.862s
• macOS: 1.486s
• Ubuntu: 2.393s

This test suite significantly enhances the reliability of the i.smap module by covering both core functionalities and edge cases. Looking forward to feedback and potential refinements!

[petrasovaa]

This should be different type, no?

[jayneel-shah18]

Fixed it to use i.signatures remove.