Stop propagation of combobox keyboard events (#931)

Stop propagation of combobox keyboard events

This commit adds a missing `stopPropagation` call in the combobox's
keyboard event handling in order to prevent those events from bubbling
to other elements.

Author: haukesomm

headless/src/jsMain/kotlin/dev/fritz2/headless/components/Combobox.kt

@@ -569,6 +569,9 @@ class Combobox<E : HTMLElement, T>(tag: Tag<E>, id: String?) : Tag<E> by tag, Op
                     keydownsIf {
                         if (shortcutOf(this) in (itemActivationKeys + Keys.Enter)) {
                             preventDefault()
+                            // Using stopImmediatePropagation() would prevent the event from being handled in all
+                            // relevant places
+                            stopPropagation()
                             true
                         } else false
                     }.map { event ->