Enhance school creation and staffing management with native language support

- Updated protocol documentation to include `nativeLanguages` in `nameSets` and added `nativeLanguage` to school creation options.
- Enhanced the UI for school creation to allow selection of native languages, improving user experience.
- Revised API interfaces to accommodate new native language features, ensuring proper data handling.
- Improved localization strings to support new native language functionalities in both English and Russian.
- Updated tests to validate the new native language features and ensure robust functionality in staffing scenarios.

tests/HSchool.People.Tests/YearlyIntakeTests.cs

@@ -118,5 +118,8 @@ public class YearlyIntakeTests
 
     private static string Snapshot(Roster roster) =>
         string.Join('\n', roster.People.Select(person =>
-            $"{person.Id}|{person.FamilyId}|{person.IsStudent}|{person.IsStaff}|{person.IsParent}|{person.ClassId}|{person.Name.Full}"));
+            $"{person.Id}|{person.FamilyId}|{person.IsStudent}|{person.IsStaff}|{person.IsParent}|{person.ClassId}|{person.Name.Full}|{Skills(person)}"));
+
+    private static string Skills(Person person) =>
+        string.Join(',', person.Skills.OrderBy(pair => pair.Key, StringComparer.Ordinal).Select(pair => $"{pair.Key}={pair.Value}"));
 }