fix: Fractional index validation (#11258)

- Vendored fractional-indexing and converted to TypeScript
- Stricter index format validation in fractional-indexing
- Added format validation to fractional index validation

---
Signed-off-by: Mark Tolmacs <mark@lazycat.hu>
Co-authored-by: dwelle <5153846+dwelle@users.noreply.github.com>

scripts/release.js

@@ -6,7 +6,13 @@ const { execSync } = require("child_process");
 const updateChangelog = require("./updateChangelog");
 
 // skipping utils for now, as it has independent release process
-const PACKAGES = ["common", "math", "element", "excalidraw"];
+const PACKAGES = [
+  "common",
+  "fractional-indexing",
+  "math",
+  "element",
+  "excalidraw",
+];
 const PACKAGES_DIR = path.resolve(__dirname, "../packages");
 
 /**