Add generic Nextcloud icon (copy of cloud icon)

packages/common/assets/icons/nextcloud.svg

+<?xml version="1.0" encoding="utf-8"?>
+<!-- Generator: Adobe Illustrator 21.0.2, SVG Export Plug-In . SVG Version: 6.00 Build 0)  -->
+<svg version="1.1" id="Layer_1" xmlns="http://www.w3.org/2000/svg" xmlns:xlink="http://www.w3.org/1999/xlink" x="0px" y="0px"
+	 viewBox="0 0 100 100" style="enable-background:new 0 0 100 100;" xml:space="preserve">
+<g>
+	<path d="M69.3,86.1l-46.1,0C11,85.9,1.1,75.9,1.1,63.7c0-11.8,9.1-21.4,20.6-22.4c0.5-15.2,13-27.4,28.3-27.4
+		c3.4,0,6.6,0.5,9.2,1.6c6.2,2.1,11.4,6.4,14.8,12c6.5,1,12.7,4.3,16.9,9.1c5,5.5,7.8,12.6,7.8,19.9C98.8,72.8,85.6,86.1,69.3,86.1z
+		 M23.6,80.6h45.7c13.3,0,24-10.8,24-24c0-6-2.3-11.8-6.4-16.2c-3.7-4.2-9.1-6.9-14.9-7.5l-1.4-0.2L70,31.4
+		c-2.8-5.1-7.2-8.9-12.6-10.7l-0.1,0c-2-0.8-4.5-1.2-7.2-1.2c-12.6,0-22.9,10.3-22.9,22.9v4.5h-3.6c-9.3,0-17,7.6-17,17
+		C6.6,73,14.3,80.6,23.6,80.6z"/>
+</g>
+</svg>