[UX] [i18n] Use enter separator rather than comma in highlight preferences

[mnlbox]

Hi guys,
I want talk about this part of app:

I think it's better to use Enter character as a separator rather than comma in highlight preferences because comma in any language is difference for example in Arabic comma is ، but in English is , so it's so difficult to use highlight feature in other language with below steps:

1. Type a word in Arabic
2. Switch keyboard layout to English
3. Type a comma
4. Switch keyboard layout to Arabic
5. Type another word

If we use Enter as a separator this feature can be more useful for non-English users.
I find related code here:

https://github.com/RocketChat/Rocket.Chat/blob/develop/packages/rocketchat-ui-account/client/accountPreferences.js#L156

[mnlbox]

#8175

[cyclops24]

@mnlbox, @karlprieb, @engelgabriel It's can be a useful improvement. 👍