Add search aliases for recently-added languages

Adding a test to ensure that both Tongan (to) and
Chitonga can be found by searching for "tonga".
Other cases are trivial and don't require a test.

Bug: T368046
Bug: T368856
Bug: T369464
Change-Id: Ia58f593729de1302749eeba349979a1a23e4eb4c

tests/phpunit/LanguageSearchTest.php

@@ -102,6 +102,21 @@ class LanguageSearchTest extends PHPUnit\Framework\TestCase {
 				'ka' => 'qartuli',
 			]
 			],
+			[ 'tonga', [
+				'to' => 'tonga',
+				'tog' => 'tonga (niasa)',
+				'toi' => 'tonga, chi-',
+				'ts' => 'tsonga',
+				'nr' => 'tonga — enetepēra ki te tonga',
+				'hax' => 'tonga — haira ki te tonga',
+				'st' => 'tonga — hōto ki te tonga',
+				'es-419' => 'tonga — pāniora amerikana ki te tonga',
+				'slh' => 'tonga — ratūti ki te tonga',
+				'tce' => 'tonga — tatōne ki te tonga',
+				'alt' => 'tonga — ātai ki te tonga',
+				'crj' => 'tonga-mā-rāwhiti — kirī tonga-mā-rāwhiti',
+			]
+			],
 			[ 'valencia', [
 				'ca' => 'valencia',
 			]