Implement support for parsing/interacting with NCAs. (#942)

* fs: implement support for interacting with ncas.

* spl: extend to use virtual keyslots

libraries/libstratosphere/source/hos/hos_version_api.cpp

@@ -49,6 +49,14 @@ namespace ams::hos {
         return g_hos_version;
     }
 
+
+    void SetVersionForLibnxInternalDebug(hos::Version debug_version) {
+        std::scoped_lock lk(g_mutex);
+        g_hos_version = debug_version;
+        __atomic_store_n(&g_has_cached, true, __ATOMIC_SEQ_CST);
+        SetVersionForLibnxInternal();
+    }
+
     void SetVersionForLibnxInternal() {
         const u32 hos_version_val = static_cast<u32>(hos::GetVersion());
         const u32 major = (hos_version_val >> 24) & 0xFF;