MVP: Improve token detection

[sethkfman]

Description

As a user, I want better auto-detection of my tokens (without clicking the 'Import tokens' button)
Epic page

Situation

Currently

• Token detection happens with eth-contract-metadata

The change:

• (new) Shared token detection controller that pulls token information from the API, and pushes it to UI → display the newly token detected tokens in the account's token list
• Condition of only showing tokens that have 2+ occurrences AND token has non-zero balance

Technical Background

• Use Token Service API to display tokens with non-zero balance that have 2+ occurrences.
• Slack Conversation on Controller: https://consensys.slack.com/archives/C021WBTTT63/p1622763578016000
• Controller PR: Adding TokenListController to fetch the token list from token services API core#478

Extension:

Mobile:

Updated Figma MVP on Mobile (July 2, 2021)

https://www.figma.com/file/1QISZ3M6lUs9i5uFUPK5Xu/Token-Detection-V1-(mobile)?node-id=665%3A11998

Out-of-Scope

• Design work
• Figma file for big picture reference
• Design Github ticket