fix(CssManager): Make CssManager a singleton and export the shared instance via getSingleton; update tests and dependencies

test/test.chromium.ts

@@ -0,0 +1,24 @@
+import { expect, tap } from '@push.rocks/tapbundle';
+import * as deesElement from '../ts/index.js';
+
+tap.test('should create a static element', async () => {
+  @deesElement.customElement('my-button')
+  class MyButton extends deesElement.DeesElement {
+    // STATIC
+    public static styles = [
+      deesElement.cssManager.defaultStyles,
+      deesElement.css`
+      .buttonClass {
+        background: ${deesElement.cssManager.bdTheme('blue', 'black')};
+      }
+    `,
+    ];
+
+    // INSTANCE
+    render() {
+      return deesElement.html`<div class="buttonClass">My Button</div>`;
+    }
+  }
+});
+
+tap.start();