Release 5.0.2 with error source fix for some downstream errors (#1980)

This PR fixes error source for 2 errors:
- parsing of invalid json response should be downstream error as we
expect to receive valid json from zabbix
- no host found error should be downstream. We are bumping sdk that
includes that fix
https://github.com/grafana/grafana-plugin-sdk-go/pull/1246.

As you can see - the invalid json parsing is now downstream error
<img width="1498" alt="image"
src="https://github.com/user-attachments/assets/88028dbe-0f73-47aa-8262-5729059ce12f"
/>

pkg/zabbixapi/zabbix_api.go

@@ -196,7 +196,8 @@ func isDeprecatedUserParamError(err error) bool {
 func handleAPIResult(response []byte) (*simplejson.Json, error) {
 	jsonResp, err := simplejson.NewJson([]byte(response))
 	if err != nil {
-		return nil, err
+		// Response is not valid JSON
+		return nil, backend.DownstreamError(err)
 	}
 	if errJSON, isError := jsonResp.CheckGet("error"); isError {
 		errMessage := fmt.Errorf("%s %s", errJSON.Get("message").MustString(), errJSON.Get("data").MustString())

pkg/zabbixapi/zabbix_api_test.go

@@ -71,3 +71,54 @@ func TestZabbixAPI(t *testing.T) {
 		})
 	}
 }
+
+func TestHandleAPIResult(t *testing.T) {
+	tests := []struct {
+		name          string
+		response      string
+		expectedData  interface{}
+		expectedError string
+		isDownstream  bool
+	}{
+		{
+			name:         "Valid JSON with result",
+			response:     `{"result": {"data": "test"}}`,
+			expectedData: map[string]interface{}{"data": "test"},
+		},
+		{
+			name:          "Invalid JSON",
+			response:     `{"result": invalid}`,
+			expectedError: "invalid character 'i' looking for beginning of value",
+			isDownstream:  true,
+		},
+		{
+			name:          "API error response",
+			response:     `{"error": {"message": "Authentication failed", "data": "Session terminated"}}`,
+			expectedError: "Authentication failed Session terminated",
+			isDownstream:  true,
+		},
+		{
+			name:         "Empty result",
+			response:     `{"result": []}`,
+			expectedData: []interface{}{},
+		},
+	}
+
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			result, err := handleAPIResult([]byte(tt.response))
+
+			if tt.expectedError != "" {
+				assert.Error(t, err)
+				assert.Equal(t, tt.expectedError, err.Error())
+				if tt.isDownstream {
+					assert.True(t, backend.IsDownstreamError(err), "error should be a downstream error")
+				}
+				return
+			}
+
+			assert.NoError(t, err)
+			assert.Equal(t, tt.expectedData, result.Interface())
+		})
+	}
+}