feat: Add dropdownOnly option to Text (#3683)

* feat: add dropdownOnly option

* Update docs

Co-authored-by: Grzegorz Karaluch <grzegorz.karaluch@sap.com>

* fix formatting

---------

Co-authored-by: Grzegorz Karaluch <grzegorz.karaluch@sap.com>

Author: OliwiaGowor

docs/extensibility/60-form-widgets.md

@@ -40,6 +40,7 @@ These are the available `Text` widget parameters:
 | **decodable**         | No       | boolean             | Specifies that the field is base64-encoded and can be decoded in the UI. It can't be used together with **enum**.                                                                                                    |
 | **decodedPlacehoder** | No       | string              | An optional alternative placeholder to use when the field is decoded.                                                                                                                                                |
 | **disableOnEdit**     | No       | boolean             | Disables a field in edit mode, defaults to `false`. Ignored if **readOnly** is set to `true`.                                                                                                                        |
+| **dropdownOnly**      | No       | boolean             | Applicable only to inputs with a dropdown. When set to `true`, it restricts user input, allowing selection only from the predefined options. Defaults to `false`.                                                    |
 
 See the following examples:
 

src/components/Extensibility/components-form/StringRenderer.js

@@ -85,7 +85,12 @@ export function StringRenderer({
         };
       });
 
-      return { input: Inputs.ComboboxInput, options: displayOptions };
+      return {
+        input: schema.get('dropdownOnly')
+          ? Inputs.Dropdown
+          : Inputs.ComboboxInput,
+        options: displayOptions,
+      };
     } else if (!decodable) {
       return { input: Inputs.Text };
     } else {