Clean and update locales (#1402)

* Remove untranslated languages

* Add country prefix to some locales

* Remove locale template file

* Prepare nl_NL and tr_TR locale for future use

* Sort locales list and put en_Us at the top

* Enhance locale Makefile

Add clean target for locales

Set locale all target to clean and build

Ensure we keep issue tracker on po updates

* Update locales headers

* Scan sources files and update locales

legacy/application/models/Locale.php

@@ -5,13 +5,13 @@ final class Application_Model_Locale
     private static $domains = ['libretime'];
 
     public static $locales = [
-        'en_CA' => 'English (Canada)',
-        'en_GB' => 'English (Britain)',
         'en_US' => 'English (USA)',
         'cs_CZ' => 'Český',
-        'de_DE' => 'Deutsch',
         'de_AT' => 'Deutsch (Österreich)',
+        'de_DE' => 'Deutsch',
         'el_GR' => 'Ελληνικά',
+        'en_CA' => 'English (Canada)',
+        'en_GB' => 'English (Britain)',
         'es_ES' => 'Español',
         'fr_FR' => 'Français',
         'hr_HR' => 'Hrvatski',
@@ -19,11 +19,13 @@ final class Application_Model_Locale
         'it_IT' => 'Italiano',
         'ja_JP' => '日本語',
         'ko_KR' => '한국어',
+        // 'nl_NL' => '',
         'pl_PL' => 'Polski',
         'pt_BR' => 'Português (Brasil)',
         'ru_RU' => 'Русский',
         'sr_RS' => 'Српски (Ћирилица)',
         'sr_RS@latin' => 'Srpski (Latinica)',
+        // 'tr_TR' => '',
         'zh_CN' => '简体中文',
     ];