Add support Thai translations
minor #10708 Add support Thai translations (liverbool)

This PR was squashed before being merged into the 2.3 branch (closes #10708).

Discussion
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Add support Thai translations

Add [Thai](http://www.thai-language.com/) translations to:
+ Symfony/Component/Validator/Resources/translations/
+ Symfony/Component/Security/Resources/translations/

Commits
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4bc2951 Add support Thai translations