fix: make nested navigator params required

previously nested navigator params always included `| undefined`.
this made it possible to cause a crash by allowing navigating to nested
navigator without reequired params.

this improves the types to make them required, and only make it optional
if all nested params are optional.

it's a bit stricter than runtime, as it can depend on initial route for
a stack,
but for now this is a safer option than making it always optional.

Author: satya164

example/__typechecks__/common.check.tsx

@@ -726,6 +726,7 @@ useLinkProps<RootStackParamList>({ screen: 'Login' });
   Timeline
 </Button>;
 
+// @ts-expect-error
 useLinkProps({ screen: 'StackBasic' });
 // @ts-expect-error
 useLinkProps({ screen: 'StackBasi' });
@@ -739,6 +740,7 @@ useLinkProps({
   params: { screen: 'Examples' },
 });
 
+// @ts-expect-error
 <Link screen="StackBasic">StackBasic</Link>;
 // @ts-expect-error
 <Link screen="StackBasi">StackBasic</Link>;
@@ -750,6 +752,7 @@ useLinkProps({
   Home
 </Link>;
 
+// @ts-expect-error
 <Button screen="StackBasic">StackBasic</Button>;
 // @ts-expect-error
 <Button screen="StackBasi">StackBasic</Button>;