showing feedback when starting a new connection

[edublancas]

we're currently not displaying any feedback when creating a new connection, but we should display something like "Connected to {alias}". This should be configurable and turned off when feedback=0

Likewise, the "switching to connection" messages should be turned off when feedback=0

you can get the current feedback level with: https://github.com/ploomber/jupysql/blob/master/src/sql/_current.py

[bbeat2782]

Acceptance Criteria

1. Display a Connected to {alias} message that is configurable with feedback=0 when starting the first connection
2. Add test functions