Fix inline link elements bug (#995)

* fix: bug when inlined link elements

* test: update snapshot for test cases

* apply Justin's review suggestions

1. make Mirror's replace function act the same with the original one when there's no existed node to get replaced.
2. when replacing with the link/style elements, keep their existing attributes to prevent potential bugs

packages/rrdom/src/index.ts

@@ -389,6 +389,11 @@ export class Mirror implements IMirror<RRNode> {
   }
 
   replace(id: number, n: RRNode) {
+    const oldNode = this.getNode(id);
+    if (oldNode) {
+      const meta = this.nodeMetaMap.get(oldNode);
+      if (meta) this.nodeMetaMap.set(n, meta);
+    }
     this.idNodeMap.set(id, n);
   }