Add icons at missing sizes, clean up SVG metadata

Adds app icon at 24px, 32px, 64px, 96px. This should give a
cleaner look in system menus like App Finder, Whisker Menu.

Removes export path strings from SVGs, metadata which Inkscape added on export.

Note:
Inkscape has recently changed this to use relative
paths so it shouldn't be an issue in the future.

data/icons/24x24/org.xfce.taskmanager.svg

@@ -0,0 +1,111 @@
+<?xml version="1.0" encoding="UTF-8" standalone="no"?>
+<svg
+   width="24"
+   height="24"
+   id="svg11300"
+   version="1.0"
+   style="display:inline;enable-background:new"
+   viewBox="0 0 24 24"
+   sodipodi:docname="org.xfce.taskmanager.svg"
+   inkscape:version="1.2.2 (b0a8486541, 2022-12-01)"
+   inkscape:export-filename="org.xfce.taskmanager.png"
+   inkscape:export-xdpi="96"
+   inkscape:export-ydpi="96"
+   xmlns:inkscape="http://www.inkscape.org/namespaces/inkscape"
+   xmlns:sodipodi="http://sodipodi.sourceforge.net/DTD/sodipodi-0.dtd"
+   xmlns="http://www.w3.org/2000/svg"
+   xmlns:svg="http://www.w3.org/2000/svg"
+   xmlns:rdf="http://www.w3.org/1999/02/22-rdf-syntax-ns#"
+   xmlns:cc="http://creativecommons.org/ns#"
+   xmlns:dc="http://purl.org/dc/elements/1.1/">
+  <sodipodi:namedview
+     pagecolor="#ffffff"
+     bordercolor="#666666"
+     borderopacity="1"
+     objecttolerance="10"
+     gridtolerance="10"
+     guidetolerance="10"
+     inkscape:pageopacity="0"
+     inkscape:pageshadow="2"
+     inkscape:window-width="1327"
+     inkscape:window-height="875"
+     id="namedview44"
+     showgrid="true"
+     inkscape:zoom="22.627418"
+     inkscape:cx="9.1039994"
+     inkscape:cy="11.402096"
+     inkscape:window-x="591"
+     inkscape:window-y="61"
+     inkscape:window-maximized="0"
+     inkscape:current-layer="svg11300"
+     inkscape:lockguides="true"
+     showguides="true"
+     inkscape:guide-bbox="true"
+     inkscape:pagecheckerboard="false"
+     inkscape:showpageshadow="2"
+     inkscape:deskcolor="#d1d1d1">
+    <inkscape:grid
+       type="xygrid"
+       id="grid4761"
+       empspacing="4"
+       originx="0"
+       originy="0" />
+    <sodipodi:guide
+       position="6,64"
+       orientation="0,1"
+       id="guide846"
+       inkscape:locked="true"
+       inkscape:label=""
+       inkscape:color="rgb(0,0,255)" />
+  </sodipodi:namedview>
+  <title
+     id="title4162">Adwaita Icon Template</title>
+  <defs
+     id="defs3">
+    <linearGradient
+       id="linearGradient1020"
+       inkscape:swatch="gradient">
+      <stop
+         style="stop-color:#ffffff;stop-opacity:1;"
+         offset="0"
+         id="stop1016" />
+      <stop
+         style="stop-color:#ffffff;stop-opacity:0.09411765"
+         offset="1"
+         id="stop1018" />
+    </linearGradient>
+  </defs>
+  <metadata
+     id="metadata4">
+    <rdf:RDF>
+      <cc:Work
+         rdf:about="">
+        <dc:title>Adwaita Icon Template</dc:title>
+      </cc:Work>
+    </rdf:RDF>
+  </metadata>
+  <rect
+     style="display:inline;opacity:1;fill:#d2d8dc;fill-opacity:1;stroke:#a7b0b7;stroke-width:0.999998;stroke-linecap:butt;stroke-linejoin:miter;stroke-miterlimit:4;stroke-dasharray:none;stroke-dashoffset:0;stroke-opacity:1;marker:none;marker-start:none;marker-mid:none;marker-end:none;paint-order:normal;enable-background:new"
+     id="rect929-36-9-9"
+     width="19"
+     height="18"
+     x="2.5"
+     y="2.5"
+     ry="1.4999996"
+     rx="1.5" />
+  <rect
+     style="display:inline;opacity:1;fill:#162631;fill-opacity:1;stroke:none;stroke-width:0.999999;stroke-linecap:butt;stroke-linejoin:miter;stroke-miterlimit:4;stroke-dasharray:none;stroke-dashoffset:0;stroke-opacity:1;marker:none;marker-start:none;marker-mid:none;marker-end:none;paint-order:normal;enable-background:new"
+     id="rect946-0-7-4"
+     width="16"
+     height="15"
+     x="4"
+     y="4"
+     ry="1"
+     rx="1" />
+  <path
+     id="path1092-6-1-3-7-5-1-0"
+     style="display:inline;opacity:1;fill:none;stroke:#00aade;stroke-width:1;stroke-linecap:round;stroke-linejoin:miter;stroke-miterlimit:10;stroke-dasharray:none;stroke-opacity:1;enable-background:new"
+     d="M 5,11.5 H 6.5 L 8,8 l 2.5,7.5 1.5,-4 h 1.423489 L 15,9 16.5,11.5 H 19"
+     inkscape:connector-curvature="0"
+     sodipodi:nodetypes="ccccccccc" />
+</svg>