{{yichen1-ai-5172-refactor-hd-matching}}

PR description

refactor matching functions, including

1. change sqrt term to linear approximation in normalization
2. add option of separate_half_matching to HammingDistanceMatcher so it can be computed with or without separating iris to upper and lower halves.
3. remove option of nm_type, only keep linear fusion when separate_half_matching is enabled.
4. refactor utils.py and reduce lines of code by 60

Issue

Solution

Limitations

Type

• Feature
• Refactoring
• Bugfix
• DevOps
• Testing

Checklist

• I've made sure that my code works as expected by writing unit tests.
• I've checked if my code doesn't generate warnings or errors.
• I've performed a self-review of my code.
• I've made sure that my code follows the style guidelines of the project.
• I've commented hard-to-understand parts of my code.
• I've made appropriate changes in the documentation.