feat(native): update set_user calls to use new new_user function output

platform-includes/enriching-events/scopes/configure-scope/native.mdx

@@ -5,8 +5,7 @@ The Native SDK maintains all data in a single global scope.
 
 sentry_set_tag("my-tag", "my value");
 
-sentry_value_t user = sentry_value_new_object();
-sentry_value_set_by_key(user, "id", sentry_value_new_int32(42));
-sentry_value_set_by_key(user, "email", sentry_value_new_string("john.doe@example.com"));
+// Set a user with id, username, email, and ip_address
+sentry_value_t user = sentry_value_new_user("42", "Jane Doe", "jane.doe@example.com", "{{auto}}");
 sentry_set_user(user);
 ```

platform-includes/enriching-events/set-user/native.mdx

@@ -1,9 +1,10 @@
 ```c
 #include <sentry.h>
 
-sentry_value_t user = sentry_value_new_object();
-sentry_value_set_by_key(user, "ip_address", sentry_value_new_string("{{auto}}"));
-sentry_value_set_by_key(user, "email", sentry_value_new_string("jane.doe@example.com"));
+// Set a user with id, username, email, and ip_address
+sentry_value_t user = sentry_value_new_user("42", "Jane Doe", "jane.doe@example.com", "{{auto}}");
+// Set additional custom user data
+sentry_value_set_by_key(user, "custom_key", sentry_value_new_string("custom_value"));
 sentry_set_user(user);
 ```
 

platform-includes/sensitive-data/set-user/native.mdx

@@ -1,11 +1,8 @@
-The Native SDK maintains all data in a single global scope.
-
 ```c
 #include <sentry.h>
 
-sentry_value_t user = sentry_value_new_object();
-sentry_value_set_by_key(user, "id", sentry_value_new_int32(client_user->id));
-// OR
-sentry_value_set_by_key(user, "username", sentry_value_new_string(client_user->username));
+// At least one parameter must be non-NULL. In this case, the user value will only 
+// contain the id. username, email, and ip_address will be ignored.
+sentry_value_t user = sentry_value_new_user("42", NULL, NULL, NULL);
 sentry_set_user(user);
 ```