Collect auth metrics

Collect information about authentication performed by DAST.

{
	"event": "collect_dast_scan_auth_metrics_from_pipeline",
	
	// Columns (join, filter, fast)
	
	"property": "scan_uuid",  // join: Allows joining/distinct
	"value": 4,               // fast: browserk.AuthType (AuthNone = 0, AuthAuto = 1, 
                              //         AuthManual = 2, AuthBasicDigest = 3, AuthScript = 4
	"parameter": 0,           // fast: Success (0) or failure (define failure codes:
                              //   - 1 is generic
                              //   - 2 is panic
                              //   - others TBD)
	"label": "",              // Unused

    // JSON (slow)

                              // slow: Local storage used by auth mechanism, only include ones used
    "storage_cookie": 1,      //   count of auth cookies
    "storage_local": 1,       //   local storage used
    
                              // slow: Auth specific configuration variables set by user.
                              //       only include variables actually set by user.
                              //       specific variables may have specific value meanings
                              //       for example, 1 file vs 2 URL for script variable.
                              //       1-? -- variable set by user.
   "DAST_AUTH_USERNAME" : 1,
   "DAST_AUTH_USERNAME_FIELD" : 1,
   "DAST_AUTH_SCRIPT" : 1  // 1 - file path, 2 - URL
}

Implementation Plan

Getting struct field tags (for environment names)

	s := MyStruct{}
	t := reflect.TypeOf(s)

	for i := 0; i < t.NumField(); i++ {
		field := t.Field(i)
		jsonTag := field.Tag.Get("json")

		if jsonTag == "" {
			// No json tag, use the struct field name
			fmt.Printf("Struct Field: %s, JSON Name: %s\n", field.Name, field.Name)
		} else if jsonTag == "-" {
			// Field is explicitly ignored with json:"-"
			fmt.Printf("Struct Field: %s, JSON Name: (ignored)\n", field.Name)
		} else {
			// Extract the actual JSON name (before any options like ",omitempty")
			jsonName := jsonTag
			if commaIndex := findComma(jsonTag); commaIndex != -1 {
				jsonName = jsonTag[:commaIndex]
			}
			fmt.Printf("Struct Field: %s, JSON Name: %s\n", field.Name, jsonName)
		}
	}