Add 'STAKE LIST' to Portfolio dAPP Features

**Description: The Stake List (or whatever the MetaMask team decides to name it) will display the tokens or nfts the user staked and how much its worth.

**Purpose: This feature is to show the token or nft the user staked on supported stake sites and to enable seamless monitoring of the activities going on with all the staked assets.

Extension/Mobile/Both: Both