connection: create a `get()` helper for connection objects
connection: create a `get()` helper for connection objects

Based on the input (with sane defaults) it will return the right backend
connection object

Signed-off-by: Alfredo Deza <a527f45c4d359ddc0a14b8fd7ba6d4b9e5a271c5@deza.pe>

alfredodeza/remoto,ceph/remoto