Description

This PR introduces the Unified Asset List feature to MetaMask Mobile, providing users with a consolidated view of their assets across all supported blockchain networks. This enhancement improves the user experience by eliminating the need to switch between networks to view or manage assets, making asset management more intuitive and efficient.

We will followup with a PR to fix TS feedback we had!
(Not only TS issues but also [this](#12431 (comment) and this)

Related issues

Fixes: #12462

Manual testing steps

Build using PORTFOLIO_VIEW flag

PORTFOLIO_VIEW=true yarn watch
yarn start:ios 
yarn start:android

1. Go to the wallet page
2. Select all network on the network filter
3. Check the list of assets
4. Click on each asset with the network filter on "All Networks" and "Current Network"
5. Test send/swap flows with testnet networks to confirm everything still works
6. Importing all tokens should work when "All Networks" filter is on
7. Importing networks for a specific network should work when the "Current Network" filter is on
8. Aggregated balance should chance according to the network filter

Screenshots/Recordings

Before	After

Before

After

Pre-merge author checklist

• I’ve followed MetaMask Contributor Docs and MetaMask Mobile Coding Standards.
• I've completed the PR template to the best of my ability
• I’ve included tests if applicable
• I’ve documented my code using JSDoc format if applicable
• I’ve applied the right labels on the PR (see labeling guidelines). Not required for external contributors.

Pre-merge reviewer checklist

• I've manually tested the PR (e.g. pull and build branch, run the app, test code being changed).
• I confirm that this PR addresses all acceptance criteria described in the ticket it closes and includes the necessary testing evidence such as recordings and or screenshots.