Coinbase wallet and browser dApp to BitShares dApp integration

**Is your feature request related to a problem? Please describe.**

- Today, Aug 22 2019 Coinbase announced releasing it open source for integration.

- Today Coinbase also announced partnering with decentalized IDEX via Coinbase Walletlink.

Coinbase Wallet is a user-controlled crypto wallet and a browser for Decentralized Apps or DApps. The wallet features native support for Ethereum, ERC20 tokens, and ERC721 unique collectibles. The DApp browser works with any DApps built using web3.js.

From listing your DApp in our gallery to contacting our team, you can find what you need in these docs
https://developers.toshi.org/docs

- Coinbase Walletlink also allows entry to the following current top dApps:

Compound — On-chain borrowing and lending platform
dYdX — Margin trading, borrowing, and lending
IDEX — Decentralized exchange
Maker — Stablecoin and decentralized reserve bank
https://blog.coinbase.com/use-dapps-on-any-desktop-browser-with-coinbase-wallets-walletlink-6ca7d392ffe6

**Describe the solution you'd like**
More exposure and usage of BitShares and it's assets across large volume exchanges.
Diversification

**Describe alternatives you've considered**
0x integration

**Additional context**
The benefits outway reasons why this should not be done.

The issue mentions Coinbase Wallet, WalletLink, web3.js, and an alternative 0x integration, but names no repository files, tests, or entry points. Start by reviewing the linked Coinbase documentation and locating the existing dApp integration flow. Done should be defined as a working BitShares dApp connection with an agreed scope and acceptance criteria.

Written by the indexing model from the issue text.