Modifiers: Add icons to remaining modifier assets in Generate category

This adds new icons for the remaining two modifier Essentials assets
bundled with Blender in the `Generate` category.
(`Curve to Tube` and `Scatter on Surface`)

Pull Request: https://projects.blender.org/blender/blender/pulls/147115

release/datafiles/icons_svg/mod_curve_to_tube.svg

@@ -0,0 +1 @@
+<svg width="1700" height="1700" xmlns="http://www.w3.org/2000/svg" xmlns:inkscape="http://www.inkscape.org/namespaces/inkscape" xmlns:sodipodi="http://sodipodi.sourceforge.net/DTD/sodipodi-0.dtd"><sodipodi:namedview pagecolor="#303030" showgrid="true"><inkscape:grid id="grid5" units="px" spacingx="100" spacingy="100" color="#4772b3" opacity="0.2" visible="true" /></sodipodi:namedview><g fill="#fff"><path d="m800.29 450s291.71-27.836 341.79 249.69c76.269 422.6-391.79 550.31-591.79 550.31" fill="none" opacity=".5" stroke="#fff" stroke-linecap="round" stroke-linejoin="round" stroke-width="100"/><path d="m829.54 100.61c-32.024-0.32776-62.048 2.325-63.357 2.4414-181.28 17.901-330.28 198.67-312.97 380.07v6e-3c16.379 171.61 178.82 314.46 349.89 315.24-0.29627 7.8269-2.263 8.0558-2.5117 8.541-0.44367 0.86559-6.924 12.405-38.689 32.727-50.158 32.087-191.89 61.721-211.61 61.721-182.55 0-348.65 166.1-348.65 348.65 2e-5 182.55 166.1 348.65 348.65 348.65 169.3 0 379.49-38.643 587.38-171.63 219.16-140.2 410.1-442.48 347.52-789.25-47.716-264.39-246.66-436.21-417.55-496.05-99.781-34.944-183.55-40.553-238.09-41.111zm-1.0117 98.949c47.139 0.48264 120.9 5.6116 206.4 35.555 144.31 50.54 311.66 191.84 352.88 420.23 55.585 308-109.29 564.1-303.46 688.32-186.63 119.39-384.19 156.03-534.05 156.03-130.74 0-249.7-118.95-249.7-249.7s118.95-249.7 249.7-249.7c42.797 0 191.24-30.17 264.94-77.318 41.322-26.434 62.623-49.872 73.426-70.947 10.802-21.075 29.08-52.039 11.346-103.54-12.969-37.662-84.231-48.499-100-48.499-100 0-235.86-96.13-248.28-226.28v-4e-3c-12.398-129.93 94.344-259.41 224.2-272.2 0.87159-0.0791 24.838-2.2434 52.615-1.959z" fill="#fff"/></svg>

release/datafiles/icons_svg/mod_scatter_on_surface.svg

@@ -0,0 +1,10 @@
+<svg width="1600" height="1600" xmlns="http://www.w3.org/2000/svg" xmlns:inkscape="http://www.inkscape.org/namespaces/inkscape" xmlns:sodipodi="http://sodipodi.sourceforge.net/DTD/sodipodi-0.dtd"><sodipodi:namedview pagecolor="#303030" showgrid="true"><inkscape:grid id="grid5" units="px" spacingx="100" spacingy="100" color="#4772b3" opacity="0.2" visible="true" /></sodipodi:namedview><g fill="#fff">
+ <g transform="matrix(.92242 0 0 .92242 50.673 73.337)" fill="#fff">
+  <g transform="matrix(100 0 0 100 -36184 -55584)" enable-background="new">
+   <path d="m373.22 563.36c-2.0453 0-3.7134 1.668-3.7134 3.7134 0 2.0453 1.668 3.7134 3.7134 3.7134 2.0453 0 3.7134-1.668 3.7134-3.7134 0-2.0453-1.668-3.7134-3.7134-3.7134z"/>
+   <path d="m366.5 561.83c-1.314 0-2.3855 1.0716-2.3855 2.3855s1.0716 2.3856 2.3855 2.3856c1.314 0 2.3855-1.0716 2.3855-2.3856 0-1.314-1.0716-2.3855-2.3855-2.3855z" opacity=".85"/>
+   <path d="m368.88 557.69c-1.062 0-1.928 0.86602-1.928 1.928 0 1.0619 0.86604 1.928 1.928 1.928 1.062 0 1.928-0.86606 1.928-1.928 0-1.062-0.86606-1.928-1.928-1.928z" opacity=".6"/>
+  </g>
+ </g>
+ <path d="m242.86 200c-23.668 0.00239-42.857 19.189-42.857 42.857v349.34 51.254 56.252c23.872-44.91 58.334-83.43 100-112.34v-287.37h154.1c19.981-39.724 49.241-73.989 84.961-100h-54.928-241.28zm618.11 0c35.699 26.016 64.937 60.284 84.902 100h354.13v418.5c36.57 18.854 70.204 42.657 100 70.561v-546.21c0-23.668-19.189-42.855-42.857-42.857h-496.18zm-660.96 792.28v364.87c2e-3 23.668 19.189 42.855 42.857 42.857h527.91c-26.512-30.037-49.093-63.613-66.719-100h-404.04v-194.27c-41.715-29.236-76.15-68.158-100-113.46z" fill="#fff" opacity=".5" stroke-linecap="round" stroke-linejoin="round" stroke-width=".85714"/>
+</svg>