Added flex tab and autotranslate options

packages/rocketchat-autotranslate/client/lib/tabBar.js

...tchat-autotranslate/client/stylesheets/autotranslate.less

...chat-autotranslate/client/views/autoTranslateFlexTab.html

...etchat-autotranslate/client/views/autoTranslateFlexTab.js

packages/rocketchat-autotranslate/package.js

packages/rocketchat-autotranslate/server/autotranslate.js

...hat-autotranslate/server/methods/getSupportedLanguages.js

...s/rocketchat-autotranslate/server/methods/saveSettings.js

...s/rocketchat-autotranslate/server/models/Subscriptions.js

packages/rocketchat-autotranslate/server/settings.js

packages/rocketchat-i18n/i18n/en.i18n.json

packages/rocketchat-lib/server/models/Subscriptions.coffee

server/publications/subscription.js