Allow Snackbar to be persistent

[jamal-khey]

This pull request adds the ability to make Snackbar messages persistent. Previously, Snackbar messages would disappear after a certain amount of time, but now they can be set to stay on the screen until dismissed by the user.

[TheMaskedTurtle]

We're trying to just extend a bit the notistack API here with our snackInfo, snackWarn, etc.. methods, so it would be nice to not limit it. If so, it wouldn't require any dev to add the persist behavior as it is already in the notistack API.

[TheMaskedTurtle]

It's not really on your dev but the makeSnackbar method kind of mixes the logic of building the message and the one that just enqueue the message, maybe you could split them to make it more readable.
Something like that for the enqueue logic

const enqueue = useCallback(
        (variant: BaseVariant, snackInputs: SnackInputs) => {
            const message = makeMessage(intlRef, snackInputs);
            if (message !== undefined) {
                enqueueSnackbar(message, {
                    ...snackInputs,
                    variant,
                    style: { whiteSpace: 'pre-line' },
                });
            }
        },
        [enqueueSnackbar, intlRef]
    );

And then you keep the makeMessage with the current message logic.

[souissimai]

make style button sx={style.button}

[jamal-khey]

done