Remove more accidentally exposed methods (#723)

- Remove `FirebaseAuth.current_user_DEPRECATED`
- Add a universal rule to ignore any method ended with `LastResult_DEPRECATED`

Author: chkuang-g

app/src/swig/app.i

@@ -319,6 +319,7 @@ static firebase::AppOptions* AppOptionsLoadFromJsonConfig(const char* config) {
 %warnfilter(844);
 // Ignore all methods ending in LastResult.
 %rename("$ignore", regextarget=1) "LastResult$";
+%rename("$ignore", regextarget=1) "LastResult_DEPRECATED$";
 
 %rename(FirebaseApp) firebase::App;
 %typemap(csclassmodifiers) firebase::App "public sealed class";

auth/src/swig/auth.i

@@ -1833,7 +1833,8 @@ static CppInstanceManager<Auth> g_auth_instances;
 // * firebase::auth::UserInfoInterface::ProviderId
 
 // Deprecated method that conflicts with the CurrentUser property.
-%ignore firebase::auth::Auth::CurrentUser;
+%ignore firebase::auth::Auth::current_user;
+%ignore firebase::auth::Auth::current_user_DEPRECATED;
 // Make basic getters use C# Properties instead.
 %attributeval(firebase::auth::Auth, firebase::auth::User,
               CurrentUserInternal, current_user);