Add support for Livewire v4

[LaurinStapf]

Changes

The <script> tag is now rendered via Blade::render() and added to the json response returned by the /embed route.
On the client side, injectLivewire() consumes this tag and injects the script into the page.

Since the script is delivered through the embed payload, the helpers getLivewireAssetUri() and getLivewireUpdateUri() become obsolete from my point of view.

[LaurinStapf]

@PhiloNL have you had a chance to look into it yet?
It would be very useful to be able to upgrade the projects which are using wire-extender to Livewire v4.

[PhiloNL]

Thanks! 😄