Updated icon assets

packages/rocketchat-assets/server/assets.js

...ages/rocketchat-livechat/.app/client/views/poweredBy.html

public/favicon.ico

public/images/browserconfig.xml

public/images/logo/1024x1024-circle.png

public/images/logo/512x512.jpg

public/images/logo/512x512.png

public/images/logo/android-chrome-192x192.png

public/images/logo/android-chrome-512x512.png

public/images/logo/apple-touch-icon-precomposed.png

public/images/logo/apple-touch-icon.png

public/images/logo/favicon-16x16.png

public/images/logo/favicon-32x32.png

public/images/logo/favicon.ico

public/images/logo/logo-black.svg

public/images/logo/logo-dark.svg

public/images/logo/mstile-144x144.png

public/images/logo/mstile-150x150.png

public/images/logo/mstile-310x150.png

public/images/logo/mstile-310x310.png