feat: add 1.16.5 protocol support

- Add 1.16.5 minecraft-data
- Add v1_16_5 proto_generated code
- Add OnSuccess1_16_5 handler in client/login.go
- Update proto_generator to include 1.16.5
- Update download_minecraft_data.sh

mc/data/minecraft-data/pc/1.16.1/instruments.json

@@ -0,0 +1,66 @@
+[
+  {
+    "id": 0,
+    "name": "harp"
+  },
+  {
+    "id": 1,
+    "name": "basedrum"
+  },
+  {
+    "id": 2,
+    "name": "snare"
+  },
+  {
+    "id": 3,
+    "name": "hat"
+  },
+  {
+    "id": 4,
+    "name": "bass"
+  },
+  {
+    "id": 5,
+    "name": "flute"
+  },
+  {
+    "id": 6,
+    "name": "bell"
+  },
+  {
+    "id": 7,
+    "name": "guitar"
+  },
+  {
+    "id": 8,
+    "name": "chime"
+  },
+  {
+    "id": 9,
+    "name": "xylophone"
+  },
+  {
+    "id": 10,
+    "name": "iron_xylophone"
+  },
+  {
+    "id": 11,
+    "name": "cow_bell"
+  },
+  {
+    "id": 12,
+    "name": "didgeridoo"
+  },
+  {
+    "id": 13,
+    "name": "bit"
+  },
+  {
+    "id": 14,
+    "name": "banjo"
+  },
+  {
+    "id": 15,
+    "name": "pling"
+  }
+]