fix: inject barman sidecar in replica clusters bootstrapped with pg_basebackup (#965)

Replica clusters that use `pg_basebackup` as the bootstrap method and
stream WAL from an object store were not getting the barman sidecar
injected, causing WAL restore to fail silently. These clusters are now
handled correctly.

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Signed-off-by: Leonardo Cecchi <leonardo.cecchi@enterprisedb.com>
Signed-off-by: Armando Ruocco <armando.ruocco@enterprisedb.com>
Co-authored-by: Armando Ruocco <armando.ruocco@enterprisedb.com>