Fix macOS compilation issues

[tadam50]

Please check if the PR fulfills these requirements

• The commit message follows our guidelines
• Tests for the changes have been added (for bug fixes / features)
• Docs have been added / updated (for bug fixes / features)

Does this PR already have an issue describing the problem?
No

What kind of change does this PR introduce?
Bug fix

What is the current behavior?
MacOS build is not always sucessful on the same test failure (TestCase11SubstationGraph::testWithHvdcLines)

What is the new behavior (if this is a feature change)?
Result of compareMetadata is not a simple boolean but return expected and actual metadata.
This, in order to ba able to use assertEquals instead of assertTrue to get more information at failure

Does this PR introduce a breaking change or deprecate an API?

• Yes
• No

If yes, please check if the following requirements are fulfilled

• The Breaking Change or Deprecated label has been added
• The migration steps are described in the following section

What changes might users need to make in their application due to this PR? (migration steps)

Other information:

[flo-dup]

Why not doing the same test process than with svg or graph json? That is, in AbstractTestCase,

public abstract String toMetadata(Graph g, String filename);
public String toMetadata(Graph graph, String refMetadataName, LabelProvider labelProvider, StyleProvider styleProvider) {
  ...
}

which is then called in the unit tests by

assertEquals(toString("/metadata.json"), toMetadata(graph, "/metadata.json)

This should allow us to identify why it fails on macOS. Maybe we'll do the JsonNode comparison at the end, but here as the test issue is not completely identified we can't be sure that it's a good solution.

[sonarqubecloud]

Quality Gate passed

Issues
0 New issues
0 Accepted issues

Measures
0 Security Hotspots
No data about Coverage
0.0% Duplication on New Code

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