pm: add new 19.0.0 commands

This is functionally correct, but I have no idea what these are meant to represent.
These functions are completely unused on NX.

libraries/libvapours/include/vapours/results/pm_results.hpp

@@ -27,5 +27,6 @@ namespace ams::pm {
     R_DEFINE_ERROR_RESULT(DebugHookInUse,     4);
     R_DEFINE_ERROR_RESULT(ApplicationRunning, 5);
     R_DEFINE_ERROR_RESULT(InvalidSize,        6);
+    R_DEFINE_ERROR_RESULT(Unknown7,           7);
 
 }