Optimize Postgres database usage in the cloud-agent

### Proposed feature

Currently, the agent uses the `connect`, `agent`, and `pollux` databases.
The problem with having this architecture is the following:
- we need to maintain and run three different migration
- the number of connection pools and connections is multiplied by three
- we need to create six users accounts and three db in the Portgresql db
- we cannot fully guar
- antee data consistency as we cannot set the constraints and rules between the databases.

### Feature description

As the solution, all these data bases can be merged into one.
This will help us to maintain the consistency and optimize resource allocation (might be required in the scope of the scalability epic)

### Anything else?

_No response_