[Feature request] Make `App.create_window()` accept any `Into<String>` type for the label

[woubuc]

Is your feature request related to a problem? Please describe.
The App.create_window() function takes a label as its first argument. This currently needs to be a String so I need to use .into() on every call to this function.

Describe the solution you'd like
I'd like to be able to pass a &str label to the function without having to add .into().

Additional context
I've implemented this change on my fork to see how complicated it would be. All internal functions seem to already use impl Into<String> for labels, it's only the main public-facing function that is fixed on a String.

Changing the type to impl Into<String> will cause .into() to stop working, so since this is the public-facing API this would constitute a breaking change and developers would need to update their uses of app.create_window() when updating their Tauri version. I reckon now is the time to make a usability change like this, since Tauri is still in beta.

[chippers]

Hi, thanks for your contribution! It looks good from a cursory glance, so I suggest you open up a PR with your fork and we can make a final decision there.

One thing to be changed is the changefile level, this should be a patch not major change, and perhaps mention that it's both App and AppHandle whose signature change, since that macro is used on both.

Edit: I've opened the PR for you at #2291