Move resources/locale to Composer dependency

all remaining submodules are now non-essential to running a server.
They are also versioned and updates can be done automatically using 'composer update'.

Finally, we can also put an end to the issue of translations being rendered incorrectly or being missing due to outdated submodules.

composer.lock

@@ -4,7 +4,7 @@
         "Read more about it at https://getcomposer.org/doc/01-basic-usage.md#installing-dependencies",
         "This file is @generated automatically"
     ],
-    "content-hash": "c0368348f30e5309e979840d1cfad409",
+    "content-hash": "e36db7fb94bd79034dcc599c3029a621",
     "packages": [
         {
             "name": "adhocore/json-comment",
@@ -531,6 +531,29 @@
             },
             "time": "2021-02-12T18:56:22+00:00"
         },
+        {
+            "name": "pocketmine/locale-data",
+            "version": "1.0.3",
+            "source": {
+                "type": "git",
+                "url": "https://github.com/pmmp/Language.git",
+                "reference": "7342b4eb593036c739e7f0c0ed95299ada69ff19"
+            },
+            "dist": {
+                "type": "zip",
+                "url": "https://api.github.com/repos/pmmp/Language/zipball/7342b4eb593036c739e7f0c0ed95299ada69ff19",
+                "reference": "7342b4eb593036c739e7f0c0ed95299ada69ff19",
+                "shasum": ""
+            },
+            "type": "library",
+            "notification-url": "https://packagist.org/downloads/",
+            "description": "Language resources used by PocketMine-MP",
+            "support": {
+                "issues": "https://github.com/pmmp/Language/issues",
+                "source": "https://github.com/pmmp/Language/tree/1.0.3"
+            },
+            "time": "2021-11-06T00:27:03+00:00"
+        },
         {
             "name": "pocketmine/log",
             "version": "0.4.0",