feat(ingestion): only index emails that are not already present

[zereraz]

the emails don't change in terms of who has access to them we should not be reingesting them, so if an email already exists then we don't have to ingest them.
if it is first time ingestion then we can ignore it, if it is not but a restart(need to figure out how to detect this) then we move to the checking and then ingestion.

[zereraz]

We can check if ingestion is already existing by a connector in connecting state and then we also need to detect and start ingestion