refactor(tangle-dapp): Update restaking page organization

[yurixander]

Summary of changes

Provide a detailed description of proposed changes.

• ➕ Added missing 404 page.
• ➕ Added and implemented a generic list modal component that allows the selection of various things, such as operators, assets, etc. This will help improve consistency in design, search/filtering, and also empty & loading states ([TASK] Standardize & unify list-style modals #2715).
• 🔧 Moved the positioning and layout of the restake actions to be under a Restake tab.
• 🎨 Made some design updates to match the updated designs in Figma (eg. updating the button's disabled state background color, smaller paddings for cards, etc.).
• 🎨 Fixed a design bug where the purple background gradient wasn't shown on light theme.
• 🎨 Fixed icon sizing which caused all icons to be overly large.
• 🐛 Fixed some bugs on mobile viewports that was causing legacy Hubble bridge information to show up.

Proposed area of change

Put an x in the boxes that apply.

• apps/tangle-dapp
• apps/tangle-cloud
• libs/tangle-shared-ui
• libs/webb-ui-components

Associated issue(s)

Specify any issues that can be closed from these changes (e.g. Closes #233).

• Closes [TASK] Update Restaking Page Organization #2678
• Closes [TASK] Add missing 404/not found page #2710
• Closes [TASK] Standardize & unify list-style modals #2715

Screen Recording

If possible provide screenshots and/or a screen recording of proposed change.

[netlify]

✅ Deploy Preview for tangle-cloud ready!

Name	Link
🔨 Latest commit	bf61d44
🔍 Latest deploy log	https://app.netlify.com/sites/tangle-cloud/deploys/6775b1586cfcc60008d42007
😎 Deploy Preview	https://deploy-preview-2711--tangle-cloud.netlify.app
📱 Preview on mobile	Toggle QR Code... Use your smartphone camera to open QR code link.

---

To edit notification comments on pull requests, go to your Netlify site configuration.

[netlify]

✅ Deploy Preview for tangle-dapp ready!

Name	Link
🔨 Latest commit	bf61d44
🔍 Latest deploy log	https://app.netlify.com/sites/tangle-dapp/deploys/6775b158c603c80008b85db9
😎 Deploy Preview	https://deploy-preview-2711--tangle-dapp.netlify.app
📱 Preview on mobile	Toggle QR Code... Use your smartphone camera to open QR code link.

---

To edit notification comments on pull requests, go to your Netlify site configuration.

[yurixander]

What's left in this PR:

• Finishing up the restake action tabs on the restake page, as they were moved from pages to tabs
• Checking design & light theme after those changes
• Checking Figma and comparing whether any other changes are missing for this task
• Center & fix design of 'No asset/operator found' modals. Currently, they appear a bit off place.
• Confirm with @monaiuu on whether some changes on the original task are still relevant or outdated.
• Finish up implementation of standardized list modals.