Add SVG image for extruder button

CURA-4211

resources/themes/cura/icons/extruder_button.svg

@@ -0,0 +1,70 @@
+<?xml version="1.0" encoding="UTF-8" standalone="no"?>
+<svg
+   xmlns:dc="http://purl.org/dc/elements/1.1/"
+   xmlns:cc="http://creativecommons.org/ns#"
+   xmlns:rdf="http://www.w3.org/1999/02/22-rdf-syntax-ns#"
+   xmlns:svg="http://www.w3.org/2000/svg"
+   xmlns="http://www.w3.org/2000/svg"
+   xmlns:sodipodi="http://sodipodi.sourceforge.net/DTD/sodipodi-0.dtd"
+   xmlns:inkscape="http://www.inkscape.org/namespaces/inkscape"
+   width="30"
+   height="30"
+   viewBox="0 0 30 30"
+   version="1.1"
+   id="svg4595"
+   sodipodi:docname="extruder_button.svg"
+   inkscape:version="0.92.2 (5c3e80d, 2017-08-06)">
+  <metadata
+     id="metadata4599">
+    <rdf:RDF>
+      <cc:Work
+         rdf:about="">
+        <dc:format>image/svg+xml</dc:format>
+        <dc:type
+           rdf:resource="http://purl.org/dc/dcmitype/StillImage" />
+        <dc:title>Artboard 3 Copy</dc:title>
+      </cc:Work>
+    </rdf:RDF>
+  </metadata>
+  <sodipodi:namedview
+     pagecolor="#ffffff"
+     bordercolor="#666666"
+     borderopacity="1"
+     objecttolerance="10"
+     gridtolerance="10"
+     guidetolerance="10"
+     inkscape:pageopacity="0"
+     inkscape:pageshadow="2"
+     inkscape:window-width="1920"
+     inkscape:window-height="1137"
+     id="namedview4597"
+     showgrid="false"
+     inkscape:pagecheckerboard="true"
+     inkscape:zoom="23.442308"
+     inkscape:cx="11.848284"
+     inkscape:cy="17.941232"
+     inkscape:window-x="2552"
+     inkscape:window-y="-8"
+     inkscape:window-maximized="1"
+     inkscape:current-layer="svg4595" />
+  <!-- Generator: Sketch 43.1 (39012) - http://www.bohemiancoding.com/sketch -->
+  <title
+     id="title4584">Artboard 3 Copy</title>
+  <desc
+     id="desc4586">Created with Sketch.</desc>
+  <defs
+     id="defs4588" />
+  <ellipse
+     id="path13"
+     cx="14.999999"
+     cy="15"
+     style="fill:none;stroke:#ffffff;stroke-width:1.5;stroke-miterlimit:4;stroke-dasharray:none;stroke-opacity:1"
+     rx="13.735848"
+     ry="13.735849" />
+  <circle
+     style="fill:none;stroke:#ffffff;stroke-width:1.39310181;stroke-miterlimit:4;stroke-dasharray:none;stroke-opacity:1"
+     id="path4509"
+     cx="24.75"
+     cy="5.25"
+     r="4.5534492" />
+</svg>