Floating Menus - UI rework (#5980)

## Summary

Enhancing and further modernizing the UI, giving users more usable area
whilst keeping farmiliar positioning and feel of elements.

## Changes

- **What**: Significant restructure of the UI elements, changing
elements from large blocks to floating elements, updating:
- Side toolbar menu (floating style, supports small/normal mode,
combines to scroll on height overflow)
- Bottom tabs panel (floating style, tabs redesigned)
- Action bar (support for docking/undocking menu)
    - Added login/user menu button to top right
- Restyled breadcrumbs (still collapse when overflows)
- Add litegraph support for fps info position (so it isn't covered by
the sidebar)

- **Breaking**: 
- Removed various elements and added new ones, I have tested custom
sidebars, custom actions, etc but if scripts are inserting elements into
"other" elements they may have been (re)moved.
- Remove support for bottom menu
- Remove support for 2nd-row tabs

## Screenshots 
<img width="1116" height="907" alt="ui"
src="https://github.com/user-attachments/assets/b040a215-67d3-4c88-8c4d-f402a16a34f6"
/>


https://github.com/user-attachments/assets/571dbda5-01ec-47e8-b235-ee1b88c93dd0

┆Issue is synchronized with this [Notion
page](https://www.notion.so/PR-5980-Floating-Menus-UI-rework-2866d73d3650810aac60cc1afe979b60)
by [Unito](https://www.unito.io)

---------

Co-authored-by: GitHub Action <action@github.com>
Co-authored-by: github-actions <github-actions@github.com>

browser_tests/tests/interaction.spec.ts

@@ -792,10 +792,19 @@ test.describe('Viewport settings', () => {
 
     await comfyPage.menu.topbar.saveWorkflow('Workflow A')
     await comfyPage.nextFrame()
-    const screenshotA = (await comfyPage.canvas.screenshot()).toString('base64')
 
     // Save workflow as a new file, then zoom out before screen shot
     await comfyPage.menu.topbar.saveWorkflowAs('Workflow B')
+
+    await comfyPage.nextFrame()
+    const tabA = comfyPage.menu.topbar.getWorkflowTab('Workflow A')
+    await changeTab(tabA)
+
+    const screenshotA = (await comfyPage.canvas.screenshot()).toString('base64')
+
+    const tabB = comfyPage.menu.topbar.getWorkflowTab('Workflow B')
+    await changeTab(tabB)
+
     await comfyMouse.move(comfyPage.emptySpace)
     for (let i = 0; i < 4; i++) {
       await comfyMouse.wheel(0, 60)
@@ -807,9 +816,6 @@ test.describe('Viewport settings', () => {
     // Ensure that the screenshots are different due to zoom level
     expect(screenshotB).not.toBe(screenshotA)
 
-    const tabA = comfyPage.menu.topbar.getWorkflowTab('Workflow A')
-    const tabB = comfyPage.menu.topbar.getWorkflowTab('Workflow B')
-
     // Go back to Workflow A
     await changeTab(tabA)
     expect((await comfyPage.canvas.screenshot()).toString('base64')).toBe(