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.

src/HSchool.People/Seed.cs

@@ -13,6 +13,8 @@ public static class Seed
     public const int HouseholdSalt = 5;
     public const int ApplicantSalt = 6;
     public const int CommuteSalt = 7;
+    public const int SkillGrantSalt = 8;
+    public const int NativeLanguageSalt = 9;
 
     /// <summary>A stream that belongs to the school rather than to one family.</summary>
     public static int ForSchool(int schoolSeed, int salt) => Mix(schoolSeed, familyIndex: -1, salt);