Backend cleanup (#146)

* Add ServerRegistration, begin refactoring to match frontend

* move graphData logic into ServerRegistration

* move ping updates/history into ServerRegistration

* start updating main app entry methods

* fix default rates.updateMojangStatus

* fix record loading delays on freshly booted instances

* move database loading logic to method + callback

* use data in frontend for type lookup instead of ping

* cleanup app.js

* reorganize methods to improve flow

* avoid useless mojang updates, remove legacy fields

* rename legacy fields for consistency

* finish restructure around App model

* ensure versions are sorted by release order

* filter errors sent to frontend to avoid data leaks

* fix version listing behavior on frontend

* 5.1.0

assets/js/servers.js

@@ -204,7 +204,7 @@ export class ServerRegistration {
       const versionsElement = document.getElementById('version_' + this.serverId)
 
       versionsElement.style.display = 'block'
-      versionsElement.innerText = formatMinecraftVersions(ping.versions, minecraftVersions[ping.info.type]) || ''
+      versionsElement.innerText = formatMinecraftVersions(ping.versions, minecraftVersions[this.data.type]) || ''
     }
 
     // Compare against a cached value to avoid empty updates
@@ -237,8 +237,7 @@ export class ServerRegistration {
       playerCountLabelElement.style.display = 'none'
       errorElement.style.display = 'block'
 
-      // Attempt to find an error cause from documented options
-      errorElement.innerText = ping.error.description || ping.error.errno || 'Unknown error'
+      errorElement.innerText = ping.error.message
     } else if (ping.result) {
       // Ensure the player-count element is visible and hide the error element
       playerCountLabelElement.style.display = 'block'