Approver app - list, CRUD operations, emails

[swcurran]

Create an approver app as described here, including the picture and the flow of the approval process.

At some point an API around the database will be needed so that both the approver and issuer apps can get at the data as they need to.

The emails can be static for now, but eventually we'll add a template capability so that we can customize them based on the user data record.

[swcurran]

Completed.