Add defaultValue for all boolean Mojo parameters defaulting to false

[Marcono1234]

Currently the Mojo documentation does not mention the default for these parameters, which will be confusing for the user. Have for example a look at the current https://maven.apache.org/plugins/maven-shade-plugin/shade-mojo.html documentation; you will see that for all the changed parameters no default value is currently documented. So it is not clear whether these parameters apply by default.

Please let me know if I forget to consider something and this change has any undesired side effects.

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