User Defined Filter
grid_filter
QgsProcessingParameterRasterLayer|INPUT|Grid|None|False
QgsProcessingParameterFeatureSource|FILTER|Filter Matrix|5|None|True
QgsProcessingParameterMatrix|FILTER_3X3|Default Filter Matrix (3x3)|3|True|1;2;3
QgsProcessingParameterRasterDestination|RESULT|Filtered Grid
