Wasm demos: add touch-action: none to all canvas

So that the Slider, Flickabke and such works on android/chrome

examples/gallery/index.html

@@ -14,6 +14,7 @@
 <style>
   canvas:focus {
     outline: none;
+    touch-action: none;
   }
 
   /* beautify ignore:start */

examples/imagefilter/index.html

@@ -19,6 +19,8 @@
             animation: spinner 1s ease infinite;
         }
         @keyframes spinner { to { transform: rotate(360deg); } }
+
+        canvas { touch-action: none; }
         /* beautify ignore:end */
     </style>
 </head>

examples/memory/index.html

@@ -19,6 +19,8 @@
             animation: spinner 1s ease infinite;
         }
         @keyframes spinner { to { transform: rotate(360deg); } }
+
+        canvas { touch-action: none; }
         /* beautify ignore:end */
     </style>
 </head>

examples/plotter/index.html

@@ -19,6 +19,8 @@
             animation: spinner 1s ease infinite;
         }
         @keyframes spinner { to { transform: rotate(360deg); } }
+
+        canvas { touch-action: none; }
         /* beautify ignore:end */
     </style>
 </head>

examples/printerdemo/rust/index.html

@@ -17,6 +17,7 @@
 
     canvas:focus {
       outline: none;
+      touch-action: none;
     }
 
     @media screen and (max-width: 992px) and (orientation: landscape) {

examples/printerdemo_old/rust/index.html

@@ -17,6 +17,7 @@
 
     canvas:focus {
       outline: none;
+      touch-action: none;
     }
 
     @media screen and (max-width: 992px) and (orientation: landscape) {

examples/slide_puzzle/index.html

@@ -8,6 +8,7 @@
 <style>
   canvas:focus {
     outline: none;
+    touch-action: none;
   }
 
   body {

examples/todo/rust/index.html

@@ -14,6 +14,7 @@
   <style>
     canvas:focus {
       outline: none;
+      touch-action: none;
     }
 
     /* beautify ignore:start */