OSM OpenMapTiles style (#1420)

* OpenMapTiles style

* Rename style snippets from layer_name.json to defaultstyle.json

* Add README to icons dir.

* Add README to icons dir.

* Rename snippets to style.json

* Fix spritezero - move icons to svg subdir

* Move icons from style/icons/svg directly to style/icons

Co-authored-by: Tomas Pohanka <TomPohys@gmail.com>

style/icons/copyshop.svg

@@ -0,0 +1,40 @@
+<?xml version="1.0" encoding="UTF-8" standalone="no"?>
+<!-- Created with Inkscape (http://www.inkscape.org/) -->
+
+<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"
+   version="1.1"
+   width="14"
+   height="14"
+   viewBox="0 0 14 14"
+   id="svg2">
+  <metadata
+     id="metadata8">
+    <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></dc:title>
+      </cc:Work>
+    </rdf:RDF>
+  </metadata>
+  <defs
+     id="defs6" />
+  <rect
+     width="14"
+     height="14"
+     x="0"
+     y="0"
+     id="canvas"
+     style="fill:none;stroke:none;visibility:hidden" />
+  <path
+     d="M 9.03125,-0.03125 1,0 1,10 4,10 4,9 2,9 2,1 l 6,0 0,2 1.03125,0 0,-3.03125 z M 3,2 3,2.5 7,2.5 7,2 3,2 z M 3,3 3,3.5 4,3.5 4,3 3,3 z M 3,4 3,4.5 4,4.5 4,4 3,4 z M 5,4 5,14 13,14 13,7.28125 9.71875,4 5,4 z M 3,5 3,5.5 4,5.5 4,5 3,5 z m 3,0 3,0 0,3 3,0 0,5 -6,0 0,-8 z M 10,5.6875 11.3125,7 10,7 10,5.6875 z M 3,6 3,6.5 4,6.5 4,6 3,6 z M 7,6 7,6.5 8,6.5 8,6 7,6 z M 3,7 3,7.5 4,7.5 4,7 3,7 z M 7,7 7,7.5 8,7.5 8,7 7,7 z M 7,8 7,8.5 8,8.5 8,8 7,8 z m 0,1 0,0.5 4,0 L 11,9 7,9 z m 0,1 0,0.5 4,0 0,-0.5 -4,0 z m 0,1 0,0.5 4,0 0,-0.5 -4,0 z"
+     id="copyshop"
+     style="fill:#ac39ac;fill-opacity:1" />
+</svg>