I want to set the default language by using command line

[johbarca]

Problem

I would like it if you provide a shortcut to set default language because if I install the language-packs, the language setting will
take effect. Now, I have a multilingual environment，so I need to change language by user interface or write settting json file, it's complicated way for me.

Proposed Solution

Provide a efficient way to set default language.

Additional context

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