fix: Parameters with default values are optional

[bfanger]

I've marked the properties of parameters that have default values as optional (x: number to x?: number)

The current situation marks the properties of the interface as required, which cause errors when properties are omitted:

Argument of type '{ x: number; }' is not assignable to parameter of type 'FlyParams'.
Type '{ x: number; }' is missing the following properties from type 'FlyParams': delay, duration, easing, y, opacity

[dkzlv]

@bfanger As far as I understand your solution would still require the developer to pass an empty object to all these animation functions like this: transition:fade={{}}.

In order to make it completely compatible to the real interface we need to make the argument itself an optional one.

[bfanger]

@dkzlv <div transition:fly> already worked without errors, I first thought this was a feature/hack of the language-server and changed the second parameter to optional, but i've reverted that change. As it turns out, when you don't provide a value for a transition svelte will call the function with an empty object as 2nd parameter.

<div transition:fly> is shorthand for <div transition:fly={{}}>

[Conduitry]

The fixed types have been published in 3.24.0.