Completed Cmix & GroupChat implementations

app/src/main/java/io/elixxir/dapp/bindings/data/Cmix.kt

...rc/main/java/io/elixxir/dapp/bindings/data/CmixAdapter.kt

app/src/main/java/io/elixxir/dapp/bindings/data/GroupChat.kt

...in/java/io/elixxir/dapp/bindings/data/GroupChatAdapter.kt

app/src/main/java/io/elixxir/dapp/bindings/model/Group.kt

.../main/java/io/elixxir/dapp/bindings/model/GroupAdapter.kt

...src/main/java/io/elixxir/dapp/bindings/model/GroupInfo.kt

...in/java/io/elixxir/dapp/bindings/model/GroupMembership.kt

...c/main/java/io/elixxir/dapp/bindings/model/GroupReport.kt

...ain/java/io/elixxir/dapp/bindings/model/HealthCallback.kt

...n/java/io/elixxir/dapp/bindings/model/HealthListenerId.kt

.../io/elixxir/dapp/bindings/model/NodeRegistrationStatus.kt

app/src/main/java/io/elixxir/dapp/user/model/User.kt