Changes

server: Add a TraceServerConfiguration host option

Allow the trace-server configuration to support an optionally specified
host string value, through the new traceserver.host system property.
Make the latter similar to (a sibling of) the existing traceserver.port.

Before this change, or if not specified, the default host value remains
0.0.0.0, or wild-card (null, code-wise). After this change, one is able
to set the listening host to another network-specific value; e.g.,
127.0.0.1.

While being in these amended files, address their minor IDE warnings and
SonarLint issues, if any and trivial. Fix surrounding formatting, too.

Change-Id: Ifb275442937df1fd248caf7102a69c4a4b5a62f1
Signed-off-by: Marco Miller <marco.miller@ericsson.com>
Reviewed-on: https://git.eclipse.org/r/c/tracecompass.incubator/org.eclipse.tracecompass.incubator/+/203543
Tested-by: Trace Compass Bot <tracecompass-bot@eclipse.org>
Tested-by: Bernd Hufmann <bernd.hufmann@ericsson.com>
Reviewed-by: Bernd Hufmann <bernd.hufmann@ericsson.com>