streamline plugin output

[hboutemy]

by default:

[INFO] --- cyclonedx:2.7.6-SNAPSHOT:makeAggregateBom (cyclonedx-makeAggregateBom) @ makeAggregateBom ---
[INFO] CycloneDX: Resolving Aggregated Dependencies
[INFO] CycloneDX: Creating BOM version 1.4 with 22 component(s)
[INFO] CycloneDX: Writing and validating BOM (XML): /path/to/CycloneDX/cyclonedx-maven-plugin/target/its/makeAggregateBom/target/bom.xml
[INFO]            attaching as makeAggregateBom-1.0-SNAPSHOT-cyclonedx.xml
[INFO] CycloneDX: Writing and validating BOM (JSON): /path/to/CycloneDX/cyclonedx-maven-plugin/target/its/makeAggregateBom/target/bom.json
[WARNING] Unknown keyword additionalItems - you should define your own Meta Schema. If the keyword is irrelevant for validation, just use a NonValidationKeyword
[INFO]            attaching as makeAggregateBom-1.0-SNAPSHOT-cyclonedx.json

notice that the WARNING is not really wanted but a separate issue (ignored until now because output was very chatty): see #305