Import doxia-core packages

[kwin]

This prevents version conflicts between doxia-sink-api (always provided by m-site-p) and doxia-core (previously loaded in the version requested via the report)

This closes #141

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[slawekjaranowski]

as maven-reporting-impl can depends on api ... maybe should also be provided?

[slawekjaranowski]

we have the same package in both:

• https://github.com/apache/maven-reporting-api/tree/master/src/main/java/org/apache/maven/reporting
• https://github.com/apache/maven-reporting-impl/tree/master/src/main/java/org/apache/maven/reporting

[kwin]

Do you have a concrete example which lead to issues that can be used as IT?

[slawekjaranowski]

not now

[kwin]

Not sure about the impact of EXCLUDES at all since imports are always considered first IIRC or am I wrong here?

[kwin]

"reporting-impl" is not provided by the parent classloader (i.e. the one from m-s-p) therefore cannot be excluded.

[github-actions]

@kwin Please assign appropriate label to PR according to the type of change.