fix(generate-schema-types): mark properties with defaults as always present in generated types

[JuanGalilea]

currently the optionalness of fields is based on the users perspective, not the actor's. This PR flips it and makes the output types match the structure that the actor receives when calling Actor.getInput()

As an example, an input schema containing:

{
  "properties": {
    "normal": { "type": "string" },
    "required": { "type": "string" },
    "defaulted": { "type": "string", "default": "hello" },
  },
  "required": ["required"]
}

The interface for the user should be:

type Input = {
  normal?: string;    // no strict requirement of it
  required: string;   // its required so we have to supply it to run the actor
  defaulted?: string; // since it has a default, its not necessary to fill it (even if made required?)
};

But the input interface as seen by the actor is:

type Input = {
  normal?: string;   // user won't necessarily supply it and its not defaulted
  required: string;  // user MUST supply it
  defaulted: string; // always there since the platform supplied a default value
};

The main use case is the last one, so as to be able to provide an interface matching the real input_schema during an actor's development cycle.

[l2ysho]

just one thing found by claude, scenarios looks valid

[l2ysho]

lgtm, thx @JuanGalilea

@vladfrangu pls also take a look

• tests locally ✅
• added some regression tests for scenarios found by claude