Add Hakka variants (hak-hans, hak-hant)

https://gerrit.wikimedia.org/r/#/c/354691/1

data/generated-langdb.json

@@ -1201,6 +1201,20 @@
             ],
             "עברית"
         ],
+        "hak-hans": [
+            "Hans",
+            [
+                "AS"
+            ],
+            "客家语（简体）"
+        ],
+        "hak-hant": [
+            "Hant",
+            [
+                "AS"
+            ],
+            "客家語（繁體）"
+        ],
         "hi": [
             "Deva",
             [

data/langdb.yaml

@@ -193,6 +193,8 @@ languages:
   hak: [Latn, [AS], Hak-kâ-fa]
   haw: [Latn, [AM, PA], Hawai`i]
   he: [Hebr, [ME], עברית]
+  hak-hans: [Hans, [AS], 客家语（简体）]
+  hak-hant: [Hant, [AS], 客家語（繁體）]
   hi: [Deva, [AS], हिन्दी]
   hif: [Latn, [PA, AS], Fiji Hindi]
   hif-deva: [Deva, [AS], फ़ीजी हिन्दी]