fix(er): switch to deterministic uuids in ER

The entity relation diagram uses uuid v4, which is randomly generated.

uuid v5 uses a SHA-1 hash, which makes the uuid deterministic.

The input strings are unique for each diagram, so this should be
okay.

packages/mermaid/src/diagrams/er/erRenderer.spec.ts

@@ -0,0 +1,12 @@
+import { generateId } from './erRenderer';
+
+describe('erRenderer', () => {
+  describe('generateId', () => {
+    it('should be deterministic', () => {
+      const id1 = generateId('hello world', 'my-prefix');
+      const id2 = generateId('hello world', 'my-prefix');
+
+      expect(id1).toBe(id2);
+    });
+  });
+});