feat(scan): create Scan tab and scannerService, implement QRScanner and controls

public/img/tab-icons/ico-scan-selected.svg

@@ -5,7 +5,7 @@
     <desc>Created with Sketch.</desc>
     <defs></defs>
     <g id="Symbols" stroke="none" stroke-width="1" fill="none" fill-rule="evenodd" stroke-linecap="round" opacity="0.9">
-        <g id="Icons/Tabs/Scan/2" transform="translate(1.000000, -6.000000)" stroke-width="1.5" stroke="#FFFFFF">
+        <g id="Icons/Tabs/Scan/2" transform="translate(1.000000, -6.000000)" stroke-width="1.5" stroke="#647CE8">
             <g id="scan" transform="translate(-1.000000, 6.000000)">
                 <g id="Scan">
                     <path d="M10.4803945,1.62179474 L6.04824505,1.62179474 M5.74546723,1.62179474 L5.74546723,5.91363686" id="Line-Copy-2" stroke-linejoin="round"></path>
@@ -17,4 +17,4 @@
             </g>
         </g>
     </g>
-</svg>
+</svg>