Which @angular/* package(s) are relevant/related to the feature request?

No response

Description

I'm experimenting now with the new resource and rxResource new APIs and one thing that is a bit hassle is that it adds undefined to the the type of it
for example I find myself needing a lot to do resource.value() ?? [] because before I was making the signal value empty array till the value is loaded

Proposed solution

is to add initial value to the ResourceOptions
points to be discussed

1. if hasValue() should be true or false if it's the initial value
2. when resource.reload() is called if it should return to the default value or not

Alternatives considered

is to keep using ?? initialValue