Define the retrieve command

[brainrepo]

Since our application needs a feature to retrieve messages from the messaging service (by default telegram),
write a command that downloads the messages and stores them using the persisted.

Acceptance criteria

• use the mock retriever to get messages
• store in the persisted
• the retriever and the persisted should be decupled (airtable persister already present in the infrastructure folder)
• this command should be run by the command line.