Adds new tile on the admin home page with system data. (#301)

* Adds new tile on the admin home page with system data. Also fixes the active users bug in the pie chart

* Fixes missing parentheses

* Updates user stats cache when signing in

* Reads active number of users from session provider

* Removes unused variable

* Small improvements

* Removes acl properties from system data websocket and performs initial push of data

* fix: remove acl fetch

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Co-authored-by: DecDuck <declanahofmeyr@gmail.com>

i18n/locales/en_us.json

@@ -280,13 +280,17 @@
       "activeInactiveUsers": "Active/inactive users",
       "activeUsers": "Active users",
       "allVersionsCombined": "All versions combined",
+      "availableRam": "({freeRam} / {totalRam})",
       "biggestGamesOnServer": "Biggest games on server",
       "biggestGamesToDownload": "Biggest games to download",
+      "cpuUsage": "CPU usage",
       "games": "Games",
       "goToUsers": "Go to users",
       "inactiveUsers": "Inactive users",
       "latestVersionOnly": "Latest version only",
       "librarySources": "Library sources",
+      "numberCores": "({count} cores) | ({count} core) | ({count} cores)",
+      "ramUsage": "RAM usage",
       "subheader": "Instance summary",
       "title": "Home",
       "users": "Users",