Page loader scaffolding

### Description

Implement a centralized loading state listener within the ff-page component.

When the loading state is active: Render a standardized UI loader overlay or skeleton.
When the loading state is inactive: Render the default component slot (the page content).
Ensure the transition between loading and content is smooth to prevent jarring layout shifts.
The loading state must be toggled via Store Actions (not local component state).
Actions should allow for optional metadata to customize the loader's appearance:
- title: (Optional) A heading to describe what is being prepared.
- description: (Optional) Subtext providing additional context to the user.
```js
// Example Store Action call
uxStore.setPageLoading(true, {
title: "Fetching Devices",
description: "Synchronizing your latest hardware status..."
});
```

NB:
Pages with multiple root elements might pose a problem with transitions