Updated the YAML parsing method (#3694)

Synchronized the process of loading and parsing YAML databases.
Provides more robust parse warnings/errors.
Added Header checks to validate database versions.
Adjusted root keys to a standard name of Body.
Adjusted inter-server storages, achievements, and attendance to follow the new format.

Fixes #3483

Thanks to @Lemongrass3110!

conf/inter_server.yml

@@ -28,7 +28,15 @@
 #	  Table: "<storage_table>"  // (string) Name of table where storage is saved. The table stucture is the same as the default storage table.
 #	  Max: <max_amount>         // (int) *optional* Maximum number of items in storage. MAX_STORAGE will be used if no value is defined.
 
-Storages:
-    - ID: 0
-      Name: "Storage"
-      Table: "storage"
+Header:
+  Type: INTER_SERVER_DB
+  Version: 1
+
+Body:
+  - ID: 0
+    Name: "Storage"
+    Table: "storage"
+
+Footer:
+  Imports:
+    - Path: conf/import/inter_server.yml