Link picker: Make link input full width if anchor option is disabled (#10313)

* Add missing focus styling

* Add width modifier to link input

* same result without adding new classes

Co-authored-by: BatJan <jaskov@gmail.com>
Co-authored-by: Jan Skovgaard Olsen <jso@co3.dk>
Co-authored-by: Nathan Woulfe <nathan@nathanw.com.au>

src/Umbraco.Web.UI.Client/src/less/property-editors.less

@@ -950,6 +950,12 @@
     .umb-linkpicker__url {
         width: 50%;
         padding-right: 5px;
+
+        // when the anchor input is hidden by config
+        // the URL input should be full-width
+        &:only-child {
+            width: 100%;
+        }
     }
 
     .umb-linkpicker__anchor {