refactor fo message buffer

context/message/sendMessage.go

context/networkManager.go

io/keyExchange/trigger.go

io/parse/partition.go

storage/garbledMessages.go

storage/messages.go

storage/session.go

storage/utility/cmixMessageBuffer.go

storage/utility/cmixMessageBuffer_test.go

storage/utility/e2eMessageBuffer.go

storage/utility/messageBuffer.go

storage/utility/messageBuffer_test.go