Core/Misc: Add console option to update databases only

Add "--update-databases-only" console argument to stop worldserver execution after having updated all databases (if specified in config file)

(cherry picked from commit 92bf5b1)

src/server/worldserver/Main.cpp

@@ -219,6 +219,9 @@ extern int main(int argc, char** argv)
     if (!StartDB())
         return 1;
 
+    if (vm.count("update-databases-only"))
+        return 0;
+
     std::shared_ptr<void> dbHandle(nullptr, [](void*) { StopDB(); });
 
     // Set server offline (not connectable)
@@ -603,6 +606,7 @@ variables_map GetConsoleArguments(int argc, char** argv, fs::path& configFile, s
         ("version,v", "print version build info")
         ("config,c", value<fs::path>(&configFile)->default_value(fs::absolute(_TRINITY_CORE_CONFIG)),
                      "use <arg> as configuration file")
+        ("update-databases-only,u", "updates databases only")
         ;
 #ifdef _WIN32
     options_description win("Windows platform specific options");