Added Turkish language.

[cemalgnlts]

I added the Turkish language into the _locales/tr/messages.json file.

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[cemalgnlts]

@googlebot I signed it!

[zainafzal08]

Thanks for uploading this change! Sadly we can't take open sourced translations due to the fact that all our translations come from trusted and verified sources, however we'll keep in mind that turkish is missing in the text app for the future!