fix: anchor tag safety (via #4789)

* v3.17.6

* release(3.17.6): rebuild dist

* add failing tests

* fix Link component

* fix OnlineValidatorBadge component

* switch from <a> to <Link> in operation components

* make Markdown inputs safe

* use Link component in Info block, for target safety

* add eslint rule for unsafe `target` usage

src/core/components/layout-utils.jsx

@@ -196,7 +196,7 @@ export class Select extends React.Component {
 export class Link extends React.Component {
 
   render() {
-    return <a {...this.props} className={xclass(this.props.className, "link")}/>
+    return <a {...this.props} rel="noopener noreferrer" className={xclass(this.props.className, "link")}/>
   }
 
 }