Refactor omni-rest-client

[msgilligan]

OmniJ OmniwalletClient could use some refactoring, maybe:

• omnij-omniwallet-api (JDK 8 interfaces only)
• omnij-omniwallet-retrofit (Retrofit-based JDK 8 client)
• omnij-omniwallet-jdk (java.net.http-based JDK 11 client)
• omnij-universal-client (APIs implemented by Omniwallet and Omni Core)

[msgilligan]

Fixed in https://github.com/OmniLayer/OmniJ/commit/d7eace38b85ccb39ef6055724d78e914d02a41ff. There may be some further package refactoring and renames of the modules/JARs. But I'm going to close this issue because that commit addresses the main issue -- removing the dependency on Retrofit in the JDK11 java.net.http client.

[msgilligan]

The actual refactoring is to three modules:

• omnij-net-api: base definitions for OmniWallet REST API and "universal" (Omni Core + Omniwallet) API
• omnij-rest-client: Retrofit-based Omniwallet client (Android-compatible)
• omnij-rest-client-mjdk: Modern JDK Omniwallet client (JDK 11+)