Deprecated mapping yaml for detections

[patel-bhavin]

adds a new mapping file for deprecated detections:

• deprecated_name: Okta Two or More Rejected Okta Pushes
  deprecated_id: d93f785e-4c2c-4262-b8c7-12b77a13fd39
  replacement_name: Okta Multiple Failed MFA Requests For User
  replacement_id: 826dbaae-a1e6-4c8c-b384-d16898956e73
  date: '2025-01-28'
  escu_version: 5.0.0
  migration_guide: https://docs.splunk.com/Documentation/ESCU/5.0.0/user/DeprecatedAnalytics
  reason: Detections updated to use the new search logic and field names due to the
  TA update

[pyth0n1c]

I have moved the deprecation information into each relevant YML file itself in line with some proposed contentctl updates.
I find this makes organization, parsing, etc much easier and more intuitive and explicit rather than keeping a separate file with mapping information.

Note that the following detections in the deprecated detections folder are still missing deprecation information in the YML and, as such, have not yet had their YMLs updated:

https://github.com/splunk/security_content/blob/deprecated_mapping/detections/deprecated/excel_spawning_windows_script_host.yml
https://github.com/splunk/security_content/blob/deprecated_mapping/detections/deprecated/windows_service_stop_via_net__and_sc_application.yml

We also lack deprecation information at this time for:

• Baselines
• Analytic Stories
• Investigations

[patel-bhavin]

Closing this in favour of #3363