[processing] add layer and field names to the statistics output (fix #10089)

Author: alexbruy

python/plugins/processing/algs/qgis/BasicStatisticsNumbers.py

@@ -145,6 +145,8 @@ def processAlgorithm(self, progress):
         iqr = stat.interQuartileRange()
 
         data = []
+        data.append('Analyzed layer: ' + layer.name())
+        data.append('Analyzed field: ' + fieldName)
         data.append('Count: ' + unicode(count))
         data.append('Unique values: ' + unicode(uniqueValue))
         data.append('Minimum value: ' + unicode(minValue))

python/plugins/processing/algs/qgis/BasicStatisticsStrings.py

@@ -125,6 +125,8 @@ def processAlgorithm(self, progress):
         uniqueValues = vector.getUniqueValuesCount(layer, index)
 
         data = []
+        data.append('Analyzed layer: ' + layer.name())
+        data.append('Analyzed field: ' + fieldName)
         data.append('Minimum length: ' + unicode(minValue))
         data.append('Maximum length: ' + unicode(maxValue))
         data.append('Mean length: ' + unicode(meanValue))