Redo Icons in SVG (#1731)

Also includes exports from SVG for all relevant files:
- `assets/icons/` in 16-1024px size PNGs
- `assets/icons/icon.ico` using same sizes as the old one
- `assets/icons/` IconTemplate
- `media/` black and white logo-only variants
- `resource/icon.png`

media/feishin.svg

@@ -0,0 +1,104 @@
+<?xml version="1.0" encoding="UTF-8" standalone="no"?>
+<!-- Created with Inkscape (http://www.inkscape.org/) -->
+
+<svg
+   width="512"
+   height="512"
+   viewBox="0 0 512 512"
+   version="1.1"
+   id="svg1"
+   xml:space="preserve"
+   xmlns:xlink="http://www.w3.org/1999/xlink"
+   xmlns="http://www.w3.org/2000/svg"
+   xmlns:svg="http://www.w3.org/2000/svg"><defs
+     id="defs1"><linearGradient
+       id="linearGradient1"><stop
+         style="stop-color:#dfdfdf;stop-opacity:1;"
+         offset="0"
+         id="stop1" /><stop
+         style="stop-color:#ffffff;stop-opacity:1;"
+         offset="1"
+         id="stop2" /></linearGradient><filter
+       style="color-interpolation-filters:sRGB"
+       id="filter249"
+       x="-0.61395349"
+       y="-0.61395349"
+       width="2.227907"
+       height="2.5069767"><feFlood
+         result="flood"
+         in="SourceGraphic"
+         flood-opacity="0.498039"
+         flood-color="rgb(0,0,0)"
+         id="feFlood247" /><feGaussianBlur
+         result="blur"
+         in="SourceGraphic"
+         stdDeviation="1.000000"
+         id="feGaussianBlur247" /><feOffset
+         result="offset"
+         in="blur"
+         dx="0.000000"
+         dy="2"
+         id="feOffset247" /><feComposite
+         result="comp1"
+         operator="in"
+         in="flood"
+         in2="offset"
+         id="feComposite248" /><feComposite
+         result="fbSourceGraphic"
+         operator="over"
+         in="SourceGraphic"
+         id="feComposite249"
+         in2="comp1" /><feColorMatrix
+         result="fbSourceGraphicAlpha"
+         in="fbSourceGraphic"
+         values="0 0 0 -1 0 0 0 0 -1 0 0 0 0 -1 0 0 0 0 1 0"
+         id="feColorMatrix122" /><feFlood
+         id="feFlood122"
+         result="flood"
+         in="fbSourceGraphic"
+         flood-opacity="0.196078"
+         flood-color="rgb(0,0,0)" /><feGaussianBlur
+         id="feGaussianBlur122"
+         result="blur"
+         in="fbSourceGraphic"
+         stdDeviation="10.000000" /><feOffset
+         id="feOffset122"
+         result="offset"
+         in="blur"
+         dx="0.000000"
+         dy="10.000000" /><feComposite
+         id="feComposite122"
+         result="comp1"
+         operator="in"
+         in="flood"
+         in2="offset" /><feComposite
+         id="feComposite123"
+         result="comp2"
+         operator="over"
+         in="fbSourceGraphic"
+         in2="comp1" /></filter><linearGradient
+       xlink:href="#linearGradient1"
+       id="linearGradient2"
+       x1="256"
+       y1="0"
+       x2="256"
+       y2="512"
+       gradientUnits="userSpaceOnUse" /></defs><g
+     id="layer1"
+     style="display:inline"><circle
+       style="display:inline;fill:url(#linearGradient2);stroke-width:25;stroke-linecap:round;stroke-linejoin:round;paint-order:markers fill stroke"
+       id="background"
+       cx="256"
+       cy="256"
+       r="256" /><circle
+       style="opacity:1;fill:#000000;fill-opacity:1;fill-rule:nonzero;stroke:none;stroke-width:2.19597;stroke-linecap:round;stroke-linejoin:round;stroke-miterlimit:4;stroke-dasharray:none;stroke-dashoffset:0;stroke-opacity:1;paint-order:markers fill stroke;filter:url(#filter249)"
+       id="dot"
+       cx="256"
+       cy="240.31155"
+       r="21.5" /><path
+       id="bottom"
+       style="opacity:1;fill:#000000;fill-opacity:1;stroke:none;stroke-width:1px;stroke-linecap:butt;stroke-linejoin:miter;stroke-opacity:1;filter:url(#filter249)"
+       d="M 220.84961,277.95117 183.5,315.59961 219.5,351.69922 239.5,332 c 0,0 5.85615,-6.19922 16.5,-6.19922 10.64385,0 16.5,6.19922 16.5,6.19922 l 20,19.69922 36,-36.09961 -37.34961,-37.64844 A 51.5,51.5 0 0 1 256,291.8125 51.5,51.5 0 0 1 220.84961,277.95117 Z" /><path
+       id="main"
+       style="display:inline;opacity:1;fill:#000000;fill-opacity:1;stroke-width:2.2;stroke-linecap:round;stroke-linejoin:round;paint-order:markers fill stroke;filter:url(#filter249)"
+       d="m 256,145.40039 c -7.11895,0 -13.56326,2.88552 -18.22852,7.55078 L 66.96875,323.46875 C 62.354158,328.08334 59.5,334.45837 59.5,341.5 c 0,14.08326 11.416739,25.5 25.5,25.5 7.04163,0 13.41666,-2.85416 18.03125,-7.46875 L 206.92578,255.93359 A 51.5,51.5 0 0 1 204.5,240.3125 a 51.5,51.5 0 0 1 51.5,-51.5 51.5,51.5 0 0 1 51.5,51.5 51.5,51.5 0 0 1 -2.42578,15.62109 L 408.96875,359.53125 C 413.58334,364.14585 419.95837,367 427,367 c 14.08326,0 25.5,-11.41674 25.5,-25.5 0,-7.04163 -2.85415,-13.41666 -7.46875,-18.03125 L 274.22852,152.95117 C 269.56326,148.2859 263.11895,145.40039 256,145.40039 Z" /></g></svg>