file-sys: Default heavy-weight class destructors in the cpp file

Several classes have a lot of non-trivial members within them, or don't
but likely should have the destructor defaulted in the cpp file for
future-proofing/being more friendly to forward declarations.

Leaving the destructor unspecified allows the compiler to inline the
destruction code all over the place, which is generally undesirable from
a code bloat perspective.

src/core/file_sys/control_metadata.h

@@ -78,6 +78,8 @@ static constexpr std::array<const char*, 15> LANGUAGE_NAMES = {
 class NACP {
 public:
     explicit NACP(VirtualFile file);
+    ~NACP();
+
     const LanguageEntry& GetLanguageEntry(Language language = Language::Default) const;
     std::string GetApplicationName(Language language = Language::Default) const;
     std::string GetDeveloperName(Language language = Language::Default) const;