[I18N] Add Chinese Simplified language support to the app

[rafaelks]

@RocketChat/ios

Thanks to Simon, who sent me the files! :-)

[codecov]

Codecov Report

Merging #2483 into develop will decrease coverage by 0.15%.
The diff coverage is n/a.

@@             Coverage Diff             @@
##           develop    #2483      +/-   ##
===========================================
- Coverage    26.38%   26.22%   -0.16%     
===========================================
  Files          456      456              
  Lines        16935    16935              
===========================================
- Hits          4469     4442      -27     
- Misses       12466    12493      +27

Impacted Files	Coverage Δ
...anagers/Model/AuthManager/AuthManagerRecover.swift	36.36% <0%> (-60.61%)	⬇️
Rocket.Chat/Extensions/Models/AuthExtensions.swift	66.66% <0%> (-33.34%)	⬇️
...Chat/Models/Subscription/SubscriptionQueries.swift	70% <0%> (-30%)	⬇️
Rocket.Chat/Managers/PushManager.swift	24.13% <0%> (-10.35%)	⬇️
Rocket.Chat/Managers/AppManager.swift	36.47% <0%> (-4.12%)	⬇️
...Chat/Controllers/Chat/MessagesViewController.swift	34.46% <0%> (+2.97%)	⬆️
...ontrollers/Base/Main/MainSplitViewController.swift	52.5% <0%> (+7.5%)	⬆️
...ocket.Chat/Extensions/Models/ObjectExtension.swift	100% <0%> (+20%)	⬆️

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