Reindent Less to 2-space (#12602)

Reindent and unify codebase to 2-space indentation.

web_src/less/_svg.less

@@ -1,9 +1,9 @@
 .svg {
-    display: inline-block;
-    vertical-align: text-top;
-    fill: currentColor;
+  display: inline-block;
+  vertical-align: text-top;
+  fill: currentColor;
 
-    .middle & {
-        vertical-align: middle;
-    }
+  .middle & {
+    vertical-align: middle;
+  }
 }