Feature Request: Default window/tray icon from toml

## Feature Request

Currently, when bundling an app with an icon option in the Dioxus.toml bundle, the provided icon will not be set for the window or trayicon (at least not on windows 11) - this is because if no icon is explicitly set, the default dioxus icon will be set instead. Preferably setting the icon in the toml file would also set it for the window and trayicon and only if none is set it would use the default.

Referenced code where default icon is loaded:
https://github.com/DioxusLabs/dioxus/blob/eaf9f80abddd75a6963edf2f48e8e21765146122/packages/desktop/src/webview.rs#L195-L204
https://github.com/DioxusLabs/dioxus/blob/eaf9f80abddd75a6963edf2f48e8e21765146122/packages/desktop/src/trayicon.rs#L37-L45