Updated .editorconfig to the newest version and reformatted the C# files accordingly

Author: abjerner

src/.editorconfig

@@ -105,7 +105,7 @@ csharp_style_unused_value_assignment_preference = discard_variable:suggestion
 csharp_style_unused_value_expression_statement_preference = discard_variable:silent
 
 # 'using' directive preferences
-csharp_using_directive_placement = outside_namespace:silent
+csharp_using_directive_placement = outside_namespace:warning
 
 #### C# Formatting Rules ####
 
@@ -127,7 +127,7 @@ csharp_indent_labels = no_change
 csharp_indent_switch_labels = true
 
 # Space preferences
-csharp_space_after_cast = false
+csharp_space_after_cast = true
 csharp_space_after_colon_in_inheritance_clause = true
 csharp_space_after_comma = true
 csharp_space_after_dot = false
@@ -194,4 +194,13 @@ dotnet_naming_style.pascal_case.capitalization = pascal_case
 dotnet_naming_style.begins_with_i.required_prefix = I
 dotnet_naming_style.begins_with_i.required_suffix = 
 dotnet_naming_style.begins_with_i.word_separator = 
-dotnet_naming_style.begins_with_i.capitalization = pascal_case
+dotnet_naming_style.begins_with_i.capitalization = pascal_case
+
+dotnet_naming_rule.instance_fields_should_be_camel_case.severity = suggestion
+dotnet_naming_rule.instance_fields_should_be_camel_case.symbols = instance_fields
+dotnet_naming_rule.instance_fields_should_be_camel_case.style = instance_field_style
+
+dotnet_naming_symbols.instance_fields.applicable_kinds = field
+
+dotnet_naming_style.instance_field_style.capitalization = camel_case
+dotnet_naming_style.instance_field_style.required_prefix = _

src/Skybrud.Umbraco.MultiNodeTreePicker/Composers/MntpComposer.cs

@@ -4,16 +4,16 @@
 using Umbraco.Cms.Core.WebAssets;
 
 namespace Skybrud.Umbraco.MultiNodeTreePicker.Composers {
-    
+
     internal sealed class MntpComposer : IComposer {
-        
+
         public void Compose(IUmbracoBuilder builder) {
             builder.WithCollectionBuilder<MntpConverterCollectionBuilder>().Add(() => builder.TypeLoader.GetTypes<IMntpItemConverter>());
             builder.BackOfficeAssets().Append<BackOfficeJavaScriptAsset>();
         }
 
         public class BackOfficeJavaScriptAsset : IAssetFile {
-        
+
             public AssetType DependencyType => AssetType.Javascript;
 
             public string FilePath { get; set; }

src/Skybrud.Umbraco.MultiNodeTreePicker/Controllers/MntpController.cs

@@ -4,7 +4,7 @@
 using Umbraco.Cms.Web.Common.Attributes;
 
 namespace Skybrud.Umbraco.MultiNodeTreePicker.Controllers {
-    
+
     [PluginController("Skybrud")]
     public class MntpController : UmbracoAuthorizedApiController {
 

src/Skybrud.Umbraco.MultiNodeTreePicker/PropertyEditors/MntpEditor.cs

@@ -2,14 +2,14 @@
 using Umbraco.Cms.Core.PropertyEditors;
 
 namespace Skybrud.Umbraco.MultiNodeTreePicker.PropertyEditors {
-    
+
     [DataEditor(EditorAlias, "Skybrud Multinode Treepicker", EditorView, ValueType = ValueTypes.Text, Group = "Skybrud.dk", Icon = "icon-page-add color-skybrud")]
     public class MntpEditor : MultiNodeTreePickerPropertyEditor {
 
         internal const string EditorAlias = "Skybrud.Umbraco.MultiNodeTreePicker";
 
         internal const string EditorView = "contentpicker";
-        
+
         private readonly IIOHelper _iOHelper;
 
         public MntpEditor(IDataValueEditorFactory dataValueEditorFactory, IIOHelper iOHelper) : base(dataValueEditorFactory, iOHelper) {

src/Skybrud.Umbraco.MultiNodeTreePicker/PropertyEditors/ValueConverters/MntpValueConverter.cs

@@ -57,15 +57,15 @@ public override object ConvertIntermediateToObject(IPublishedElement owner, IPub
             // Return "value" if the data type isn't configured with an item converter
             if (propertyType.DataType.Configuration is not MntpConfiguration config) return value;
             if (config.ItemConverter == null) return value;
-            
+
             // Get the key of the converter
             string key = config.ItemConverter.GetString("key");
-            
+
             // Return "value" if item converter wasn't found
             if (!_converterCollection.TryGet(key, out IMntpItemConverter converter)) return value;
-            
+
             switch (value) {
-                
+
                 // If "value" is a single item, we can call the converter directly
                 case IPublishedContent item:
                     return converter.Convert(propertyType, item);
@@ -110,13 +110,13 @@ public override Type GetPropertyValueType(IPublishedPropertyType propertyType) {
         }
 
         private object GetPickerValue(IPublishedPropertyType propertyType, object source, bool preview) {
-            
+
             if (source == null) return null;
 
             Udi[] udis = source as Udi[] ?? Array.Empty<Udi>();
             if (propertyType.Alias.Equals(Constants.Conventions.Content.InternalRedirectId)) return udis.FirstOrDefault();
             if (propertyType.Alias.Equals(Constants.Conventions.Content.Redirect)) return udis.FirstOrDefault();
-            
+
             // Get a reference to the current published snapshot
             _publishedSnapshotAccessor.TryGetPublishedSnapshot(out IPublishedSnapshot publishedSnapshot);
             if (publishedSnapshot == null) return source;
@@ -134,7 +134,7 @@ private object GetPickerValue(IPublishedPropertyType propertyType, object source
                 if (guidUdi == null) continue;
 
                 IPublishedContent item = null;
-                
+
                 switch (udi.EntityType) {
                     case Constants.UdiEntityType.Document:
                         item = publishedSnapshot.Content.GetById(preview, guidUdi.Guid);