[PTRun][Search]Add setting to exclude files/patterns from indexer (#31459)

* Add patterns exclusion to PTRun indexer

* Apply xaml styling

* Fix pattern escaping issues

* Add placeholder to indexer exclusion options

* Add placeholder text to textboxes

* Fix failing to split multiline text in indexer settings

* Add placeholder text to checkbox and textbox setting

* Change generated source comments to english

src/settings-ui/Settings.UI.Library/PluginAdditionalOption.cs

@@ -15,6 +15,7 @@ namespace Microsoft.PowerToys.Settings.UI.Library
             Combobox = 1,
             Textbox = 2,
             Numberbox = 3,
+            MultilineTextbox = 4,
             CheckboxAndCombobox = 11,
             CheckboxAndTextbox = 12,
             CheckboxAndNumberbox = 13,
@@ -71,6 +72,12 @@ namespace Microsoft.PowerToys.Settings.UI.Library
         [JsonIgnore(Condition = JsonIgnoreCondition.WhenWritingNull)]
         public int? TextBoxMaxLength { get; set; }
 
+        /// <summary>
+        /// Gets or sets a value for the placeholder of a textbox.
+        /// </summary>
+        [JsonIgnore(Condition = JsonIgnoreCondition.WhenWritingNull)]
+        public string PlaceholderText { get; set; }
+
         public double NumberValue { get; set; }
 
         /// <summary>