Add Nanai and Gungbe languages

Requested at translatewiki:
https://translatewiki.net/wiki/Thread:Support/please_add_Nanai_language
https://translatewiki.net/wiki/Thread:Support/_guw_Activate_new_language:_Gun_-_%27Gun

Nanai autonym according to Chemyshev and Onenko dictionary, as well as xisango.ru.

Gun autonym according to Ethnologue.

data/langdb.yaml

@@ -212,6 +212,7 @@ languages:
   gd: [Latn, [EU], Gàidhlig]
   gez: [Ethi, [AF], ግዕዝ]
   gl: [Latn, [EU], galego]
+  gld: [Cyrl, [AS], на̄ни]
   glk: [Arab, [AS, ME], گیلکی]
   gn: [Latn, [AM], "Avañe'ẽ"]
   gom: [gom-deva]
@@ -225,6 +226,7 @@ languages:
   guc: [Latn, [AM], Wayúu]
   gum: [Latn, [AM], Namtrik]
   gur: [Latn, [AF], Gurenɛ]
+  guw: [Latn, [AF], gungbe]
   gv: [Latn, [EU], Gaelg]
  # CLDR uses ha-latn and ha-arab. Latin is more common and is used in Wikipedia.
   ha-arab: [Arab, [AF], هَوُسَ]

data/language-data.json

@@ -1328,6 +1328,13 @@
             ],
             "galego"
         ],
+        "gld": [
+            "Cyrl",
+            [
+                "AS"
+            ],
+            "на̄ни"
+        ],
         "glk": [
             "Arab",
             [
@@ -1416,6 +1423,13 @@
             ],
             "Gurenɛ"
         ],
+        "guw": [
+            "Latn",
+            [
+                "AF"
+            ],
+            "gungbe"
+        ],
         "gv": [
             "Latn",
             [