add and configure UnifiedMetrics prometheus exporter

src/plugins/UnifiedMetrics/config.yml

@@ -0,0 +1,14 @@
+server:
+  name: "lobby"
+metrics:
+  enabled: true
+  driver: "prometheus"
+  collectors:
+    systemGc: true
+    systemMemory: true
+    systemProcess: true
+    systemThread: true
+    server: true
+    world: true
+    tick: true
+    events: true

src/plugins/UnifiedMetrics/driver/prometheus.yml

@@ -0,0 +1,16 @@
+mode: "HTTP"
+http:
+  host: "0.0.0.0"
+  port: 9101
+  authentication:
+    scheme: "NONE"
+    username: "username"
+    password: "password"
+pushGateway:
+  job: "unifiedmetrics"
+  url: "http://pushgateway:9091"
+  authentication:
+    scheme: "NONE"
+    username: "username"
+    password: "password"
+  interval: 10