Custom `DependencyDataImporter` implementations should be able to contribute to inputs of `ReportTask`

[erdi]

Currently only the class name of the reporter is taken as an input which in my opinion is not flexible enough.

In my use case I created an importer which aggregates many xml files via a FileCollection which contains dependency configurations with dependency xml reports from subprojects to benefit from lazy configuration. I would like to be able to make the contents of that FileCollection to be an input. Currently I have to resort to the following workaround

tasks.generateLicenseReport {
    inputs.files(aggregatedXmlLicenseReportsFileCollection)
            .withPathSensitivity(RELATIVE)
            .withPropertyName("aggregatedXmlLicenseReports")
}

I believe that this can be achieved/fixed quite easily by simply annotating LicenseReportExtension.importers with org.gradle.api.tasks.Nested.