Some Reader Functions Duplicated

[livelybug]

Some Reader functions are Duplicated.

• [ ] Read ClientStates: duplicated for 3 times. Implemented in channel.rs; Implemented in client.rs; Implemented in connection.rs
• [ ] Read ConsensusStates: duplicated 3 times
• [ ] Read Connections: duplicated 2 times
• [ ] get_channel_end: duplicated of channel_end