htc: implement htcmisc service object commands

libraries/libstratosphere/source/htc/server/htc_htcmisc_impl.hpp

@@ -55,9 +55,16 @@ namespace ams::htc::server {
             void SetServerConnectionEvent(bool en);
 
             void UpdateConnectionEvent();
+
+            void WaitTask(u32 task_id);
         public:
             void Cancel();
-            /* TODO */
+
+            Result GetEnvironmentVariable(size_t *out_size, char *dst, size_t dst_size, const char *name, size_t name_size);
+            Result GetEnvironmentVariableLength(size_t *out_size, const char *name, size_t name_size);
+
+            Result RunOnHostBegin(u32 *out_task_id, Handle *out_event, const char *args, size_t args_size);
+            Result RunOnHostEnd(s32 *out_result, u32 task_id);
     };
 
 }