ecash integration

[Amatack]

Add eCash Support to Edge Wallet

Description

This PR adds support for eCash (XEC) in Edge Wallet. Now, users will be able to send and receive eCash.

CHANGELOG

Does this branch warrant an entry to the CHANGELOG?

• [X] Yes
• [ ] No

Dependencies

This PR is related to PR #424 in the other repo

Requirements

• [ ] Tested on iOS device
• [X] Tested on Android device
• [ ] Tested on small-screen device (iPod Touch)
• [X] Tested on large-screen device (tablet)