Wallet "service" profiles

[sloops77]

WDYT about supporting user wallets into this spec?

Within Velocity Network, there are already 5 compatible wallets. Users need to select between these wallets. The wallets maybe web apps, mobile apps or browser extensions.

They always have a logo and name
They may be available under the app stores, in which case they will also have an app store name, store url, and app id