[WIP] feat: add opsgenie to migrator script

[joeyorlando]

This PR adds support for migrating data from OpsGenie to Grafana IRM.

Closes https://github.com/grafana/irm/issues/1179

Features Added

• Migration of OpsGenie resources:
  • User notification rules
  • On-call schedules (with rotations and time restrictions)
  • Escalation policies
  • Integrations
• User migration script support for OpsGenie
• Comprehensive test coverage for all migration components

Implementation Details

1. Core Migration Logic:

   • Schedule migration with support for daily, weekly, and hourly rotations
   • Escalation policy migration with proper delay handling
   • Integration migration with support for common integration types
   • User notification rules migration

2. User Migration Support:

   • Added OpsGenie user migration to add_users_to_grafana.py
   • Support for both default and EU OpsGenie instances
   • Automatic user creation with random passwords
   • Proper error handling for existing users

3. Testing:

   • Unit tests for matching logic (test_matching.py)
   • Unit tests for migration functions (test_migrate.py)
   • Unit tests for report formatting (test_report.py)
   • Unit tests for user migration (test_user_migration.py)

4. Documentation:

   • Updated README with OpsGenie-specific instructions
   • Added configuration options documentation
   • Included user migration guide
   • Added limitations and caveats

Configuration Options Added

• OPSGENIE_API_KEY: API key for OpsGenie access
• OPSGENIE_API_URL: API URL with support for EU instances
• OPSGENIE_FILTER_*: Various filtering options for selective migration
• PRESERVE_EXISTING_USER_NOTIFICATION_RULES: Option to preserve existing rules

Testing Done

• Unit tests for all major components
• Integration tests for API interactions
• Error handling verification
• Edge case testing for various resource types

Documentation Updates

• Added OpsGenie section to main README
• Documented all new environment variables
• Added user migration instructions
• Included supported integration types
• Added limitations and caveats section

[joeyorlando]

note. very much still a draft. playing around with Cursor to see what it is capable of.