DESIGN-4237 feat: 复选树支持添加自定义图标

src/less/base/tree/ztree.less

@@ -17,7 +17,7 @@
   line-height: 14px;
   text-align: left;
   white-space: pre;
-  outline: 0
+  outline: 0;
 }
 
 .ztree li ul {
@@ -73,7 +73,7 @@
   padding: 0 3px 0 0;
   margin: 0;
   cursor: pointer;
-  height: 23px;
+  height: 24px;
   background-color: transparent;
   text-decoration: none;
   vertical-align: top;
@@ -94,7 +94,7 @@
 }
 
 .ztree.solid li a {
-  height: 31px;
+  height: 32px;
 }
 
 .ztree li a.curSelectedNode {
@@ -148,6 +148,21 @@
   line-height: 32px;
 }
 
+.ztree li span.icon {
+  display: inline-block;
+  vertical-align: top;
+  text-align: center;
+  width: 24px;
+  height: 24px;
+  line-height: 24px;
+}
+
+.ztree li span.icon {
+  width: 32px;
+  height: 32px;
+  line-height: 32px;
+}
+
 .ztree li span.button {
   line-height: 0;
   margin: 0;