[processing][needs-docs] native vector split algorithm now outputs

GeoPackages instead of shapefiles (refs #20557)

Also remove default output extension Processing settings as they are not
used anymore.

(cherry picked from commit 8446d3b)

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

@@ -108,7 +108,7 @@ def processAlgorithm(self, parameters, context, feedback):
         for current, i in enumerate(uniqueValues):
             if feedback.isCanceled():
                 break
-            fName = u'{0}_{1}.shp'.format(baseName, str(i).strip())
+            fName = '{0}_{1}.gpkg'.format(baseName, str(i).strip())
             feedback.pushInfo(self.tr('Creating layer: {}').format(fName))
 
             sink, dest = QgsProcessingUtils.createFeatureSink(fName, context, fields, geomType, crs)

python/plugins/processing/core/ProcessingConfig.py

@@ -58,8 +58,6 @@ class ProcessingConfig:
     POST_EXECUTION_SCRIPT = 'POST_EXECUTION_SCRIPT'
     SHOW_CRS_DEF = 'SHOW_CRS_DEF'
     WARN_UNMATCHING_CRS = 'WARN_UNMATCHING_CRS'
-    DEFAULT_OUTPUT_RASTER_LAYER_EXT = 'DEFAULT_OUTPUT_RASTER_LAYER_EXT'
-    DEFAULT_OUTPUT_VECTOR_LAYER_EXT = 'DEFAULT_OUTPUT_VECTOR_LAYER_EXT'
     SHOW_PROVIDERS_TOOLTIP = 'SHOW_PROVIDERS_TOOLTIP'
 
     settings = {}
@@ -136,24 +134,6 @@ def initialize():
             valuetype=Setting.SELECTION,
             options=invalidFeaturesOptions))
 
-        extensions = QgsVectorFileWriter.supportedFormatExtensions()
-        ProcessingConfig.addSetting(Setting(
-            ProcessingConfig.tr('General'),
-            ProcessingConfig.DEFAULT_OUTPUT_VECTOR_LAYER_EXT,
-            ProcessingConfig.tr('Default output vector layer extension'),
-            extensions[0],
-            valuetype=Setting.SELECTION,
-            options=extensions))
-
-        extensions = QgsRasterFileWriter.supportedFormatExtensions()
-        ProcessingConfig.addSetting(Setting(
-            ProcessingConfig.tr('General'),
-            ProcessingConfig.DEFAULT_OUTPUT_RASTER_LAYER_EXT,
-            ProcessingConfig.tr('Default output raster layer extension'),
-            extensions[0],
-            valuetype=Setting.SELECTION,
-            options=extensions))
-
     @staticmethod
     def setGroupIcon(group, icon):
         ProcessingConfig.settingIcons[group] = icon