feature #45421 [Translation] Add the possibilty to export xliff translation with the .xliff suffix (DanielBadura)

This PR was squashed before being merged into the 6.1 branch.

Discussion
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 [Translation] Add the possibilty to export xliff translation with the .xliff suffix

| Q             | A
| ------------- | ---
| Branch?       | 6.1
| Bug fix?      | no
| New feature?  | yes
| Deprecations? | no
| Tickets       | -
| License       | MIT
| Doc PR        | -

Like the `YamlFileDumper` now the `XliffFileDumper` has the extension as an parameter. This enables the user to export xliff translation files with the suffix `.xlf` and `.xliff`. This is needed for example for the translation provider Lokalise and the GitLab integration for this provider.

Commits
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08c4bc58b5  [Translation] Add the possibilty to export xliff translation with the .xliff suffix

Author: fabpot

CHANGELOG.md

@@ -7,6 +7,7 @@ CHANGELOG
  * Environment variable `SYMFONY_IDE` is read by default when `framework.ide` config is not set.
  * Load PHP configuration files by default in the `MicroKernelTrait`
  * Add `cache:pool:invalidate-tags` command
+ * Add `XliffFileDumper` with `xliff` as the extension as a service
 
 6.0
 ---

Resources/config/translation.php

@@ -114,6 +114,10 @@
         ->set('translation.dumper.xliff', XliffFileDumper::class)
             ->tag('translation.dumper', ['alias' => 'xlf'])
 
+        ->set('translation.dumper.xliff.xliff', XliffFileDumper::class)
+            ->args(['xliff'])
+            ->tag('translation.dumper', ['alias' => 'xliff'])
+
         ->set('translation.dumper.po', PoFileDumper::class)
             ->tag('translation.dumper', ['alias' => 'po'])