Output round in researcher logs

MR description

Closes #425 (closed). This MR introduces the logging of the round number in the researcher logs. No such thing was introduced on the node logs, because nodes have no notion of which round thney are performing.

Developer Certificate Of Origin (DCO)

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# This file is originally part of Fed-BioMed
# SPDX-License-Identifier: Apache-2.0

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