feat: Add logging field variant versions

    # The endpoint_id of the original caller at the root of the call chain.

    ROOT_CALLER_ID = "root_caller_id"

    # Maps each field constant to its logging field variant version.

    # A version of 0 means the field is not yet assigned to any variant.

    VARIANT_VERSION = {

      CORRELATION_ID => 1,

      GL_USER_ID => 1,

      GL_USER_NAME => 1,

      DUO_WORKFLOW_DEFINITION => 0,

      ERROR_TYPE => 0,

      ERROR_MESSAGE => 1,

      HTTP_STATUS_CODE => 1,

      HTTP_METHOD => 0,

      HTTP_URL => 0,

      DURATION_S => 1,

      REMOTE_IP => 1,

      TCP_ADDRESS => 0,

      HTTP_URI => 0,

      HTTP_HOST => 0,

      HTTP_PROTO => 0,

      REMOTE_ADDR => 0,

      HTTP_REFERRER => 0,

      HTTP_USER_AGENT => 0,

      WRITTEN_BYTES => 0,

      CONTENT_TYPE => 0,

      TTFB_S => 0,

      GL_PROJECT_ID => 1,

      GL_PIPELINE_ID => 1,

      TIMESTAMP => 0,

      SEVERITY => 0,

      LOG_MESSAGE => 1,

      CLASS_NAME => 0,

      SERVICE_NAME => 0,

      GL_ORGANIZATION_ID => 1,

      GL_PROJECT_PATH => 1,

      ENDPOINT_ID => 0,

      CALLER_ID => 1,

      ROOT_CALLER_ID => 0,

    }.freeze

    # Get the constant name for a field value

    # @param field_value [String] The field value (e.g., "gl_user_id")

    # @return [String, nil] The constant name (e.g., "GL_USER_ID") or nil if not found