Impossible/inconvenient to use dioxus_desktop::Config.with_custom_event_handler()

**Problem**
It is either impossible or extremely inconvenient to use dioxus_desktop::Config::with_custom_event_handler().
The type signature `f: impl FnMut(&Event<'_, UserWindowEvent>, &EventLoopWindowTarget) + 'static,` is either very difficult or impossible to implement because `dioxus_desktop::ipc::UserWindowEvent`, the type required in the signature, is not public.

**Steps To Reproduce**

Steps to reproduce the behavior:

- Create a dioxus_desktop::Config.
- Attempt to use .with_custom_event_handler() on it.

**Expected behavior**

I expect to be able to use a custom callback to match on event loop events.

**Environment:**

- Dioxus version: 0.6.3
- Rust version: rustc 1.90.0, edition 2021
- OS info: Arch Linux
- App platform: Desktop
**Questionnaire**

I have a workaround for now, but I am wondering if this was an intentional design choice and am hesitant to use it.

The fix is to make the dioxus_desktop::ipc module public.