[13.x] Add InteractsWithData plainString method to retrieve data as a string

[devhammed]

I believe the string method in InteractsWithData should be returning actual PHP strings instead of a Stringable instance, while we keep str for that purpose because there are genuine cases where I want a nullable string, but Stringable would have already converted it to an empty string so we end up having to check for empty string or go back to using the input method. Still, since it has been used that way and changing the behaviour is a breaking change, it is only fair for us to have a way to retrieve typed data, just as there is for other types like integer, boolean, enums, arrays, etc.

[taylorotwell]

Thanks for your pull request to Laravel!

Unfortunately, I'm going to delay merging this code for now. To preserve our ability to adequately maintain the framework, we need to be very careful regarding the amount of code we include.

If applicable, please consider releasing your code as a package so that the community can still take advantage of your contributions!

[devhammed]

@taylorotwell Would you be open to making this changing the return value of the ->string() method to string|null in Laravel 14.x as mentioned here: https://x.com/sander_scode/status/2079972655424282979?