feat(libSceNpWebApi2): export sceNpWebApi2AddWebTraceTag

PPSA33016 imports sceNpWebApi2AddWebTraceTag (NID MgsTa76wlEk), and no
library exported it, so the loader stopped before the title started.
The title does not call it at start-up or in play, so the export throws
like the other unimplemented functions.

core/libs/prx/libSceNpWebApi2/Export.cpp

@@ -36,6 +36,11 @@ int APS5_VABI sceNpWebApi2AddHttpRequestHeader(int64_t request_id, const char* f
     return 0;
 }
 
+int APS5_VABI sceNpWebApi2AddWebTraceTag() {
+    NotImplemented_nid_no_patch(__func__);
+    return 0;
+}
+
 void APS5_VABI sceNpWebApi2CheckTimeout(void) {
 }