feat: add score threshold to AnalyzerEngine

[Pouyanpi]

Description

Currently the AnalyzerEngine uses default_score_threshold of 0. This PR adds score_threshold to SensitiveDataDetectionOptions so that the user can set it in the config.yml. The default value is set to 0.2 but it requires further experimentation.

Example configuration:

rails:
  config:
    sensitive_data_detection:
      input:
        score_threshold: 0.4
        entities:
          - PHONE_NUMBER
          - EMAIL_ADDRESS
          - IN_PAN
          - IN_AADHAAR

      output:
        entities:
          - PHONE_NUMBER
          - EMAIL_ADDRESS
          - IN_PAN
          - IN_AADHAAR

Related Issue(s)

• Fixes #818

Checklist

• [x] I've read the CONTRIBUTING guidelines.
• [x] I've updated the documentation if applicable.
• [x] I've added tests if applicable.
• [x] @mentions of the person or team responsible for reviewing proposed changes.