Material: MaterialTreeWidget usability enhancements

Improves the MaterialTreeWidget beyond minimum viable product.

- Filters can now be filter lists to allow a variety of filtering
	options.
- User preferences allow the inclusion/exclusion of favorites and
	recents.
- Widget state such as expansion, tree expansions, etc are saved and
	restored.
- show current appearancee material when editing.
- implements a python interface

#fixes 13421: always opens full tree

src/Mod/Material/Gui/DlgSettingsMaterial.cpp

@@ -43,6 +43,11 @@ void DlgSettingsMaterial::saveSettings()
     ui->fc_custom_mat_dir->onSave();
     ui->cb_delete_duplicates->onSave();
     ui->cb_sort_by_resources->onSave();
+    ui->cb_show_favorites->onSave();
+    ui->cb_show_recent->onSave();
+    ui->cb_show_empty_libraries->onSave();
+    ui->cb_show_empty_folders->onSave();
+    ui->cb_show_legacy->onSave();
 
     // Temporary for testing
     ui->cb_legacy_editor->onSave();
@@ -57,6 +62,11 @@ void DlgSettingsMaterial::loadSettings()
     ui->fc_custom_mat_dir->onRestore();
     ui->cb_delete_duplicates->onRestore();
     ui->cb_sort_by_resources->onRestore();
+    ui->cb_show_favorites->onRestore();
+    ui->cb_show_recent->onRestore();
+    ui->cb_show_empty_libraries->onRestore();
+    ui->cb_show_empty_folders->onRestore();
+    ui->cb_show_legacy->onRestore();
 
     // Temporary for testing
     ui->cb_legacy_editor->onRestore();