feat: anchor links (#1765)

* feat: add heading extension with unique ID support and scroll functionality
* Added unique id for heading
* remove baseUrl heading storage
* move heading to extensions package
* WIP
* support anchors in mentions
* enhance scrolling functionality
* nodeId function
* fix nanoid import
* Bring unique-id extension local
* fixes
* fix internal link scroll in public pages
* add unique id server side
* rename mention anchor to anchorId
* capture first anchorId on paste

---------

Co-authored-by: Romik <40670677+RomikMakavana@users.noreply.github.com>

packages/editor-ext/src/lib/unique-id/helpers/findDuplicates.ts

@@ -0,0 +1,11 @@
+import { removeDuplicates } from './removeDuplicates.js'
+
+/**
+ * Returns a list of duplicated items within an array.
+ */
+export function findDuplicates(items: any[]): any[] {
+  const filtered = items.filter((el, index) => items.indexOf(el) !== index)
+  const duplicates = removeDuplicates(filtered)
+
+  return duplicates
+}