Port "kernel/event: Make data members private" from yuzu (#4077)

* kernel/event: Make data members private

Instead we can simply provide accessors to the required data instead of
giving external read/write access to the variables directly.

* fix compile error

src/citra_qt/debugger/wait_tree.cpp

@@ -260,7 +260,7 @@ std::vector<std::unique_ptr<WaitTreeItem>> WaitTreeEvent::GetChildren() const {
 
     list.push_back(std::make_unique<WaitTreeText>(
         tr("reset type = %1")
-            .arg(GetResetTypeQString(static_cast<const Kernel::Event&>(object).reset_type))));
+            .arg(GetResetTypeQString(static_cast<const Kernel::Event&>(object).GetResetType()))));
     return list;
 }