Add Factorio CPU and Memory usage statistics

Add per instance metrics for CPU and memory usage with the pidusage
library.

package.json

@@ -54,6 +54,7 @@
     "needle": "^2.4.0",
     "node-factorio-api": "^0.3.8",
     "node-forge": "^0.7.1",
+    "pidusage": "^2.0.18",
     "rcon-client": "^4.2.0",
     "request": "^2.83.0",
     "sanitizer": "^0.1.3",