Add support for actions and input fields

[Akida31]

This adds some support and examples for the following actions:

• Selection
• Text
• Button/ Action

To get the values from the actions and input fields some handlers were added. These will be called by windows and execute user supplied closures.

To avoid breaking changes ToastWithHandlers won't be integrated in Toast. ToastWithHandlers requires an owned self because the handler closure will be moved. Technically it may be possible to work around this with some shared ownership of the handler closures but this could be difficult.

Should the crate get a new release so that users and other crates could use this soon?

[elibroftw]

@allenbenz hey would really appreciate if you could give the reigns for the repo to another person. It could really speed up development, developer experience, and improve the overall ecosystem. Especially for Tauri developers since this is used by Tauri indirectly.