Allow multiple prevent default for Web, Desktop and LiveView (#987)

* Allow multiple prevent default in dioxus_web

* Use SplitWhitespace for prevent default requests

* Add multiple prevent default option to liveview and desktop

* Update docs about prevent_default attribute

* cargo clippy

* update prevent default guide example

---------

Co-authored-by: Evan Almloff <ealmlof1@stumail.jccc.edu>

packages/web/src/dom.rs

@@ -55,13 +55,17 @@ impl WebsysDom {
                 let element = walk_event_for_id(event);
                 let bubbles = dioxus_html::event_bubbles(name.as_str());
                 if let Some((element, target)) = element {
-                    if target
+                    if let Some(prevent_requests) = target
                         .get_attribute("dioxus-prevent-default")
                         .as_deref()
-                        .map(|f| f.trim_start_matches("on"))
-                        == Some(&name)
+                        .map(|f| f.split_whitespace())
                     {
-                        event.prevent_default();
+                        if prevent_requests
+                            .map(|f| f.trim_start_matches("on"))
+                            .any(|f| f == name)
+                        {
+                            event.prevent_default();
+                        }
                     }
 
                     let data = virtual_event_from_websys_event(event.clone(), target);