NarUtil: add a helper method for toString impls
NarUtil: add a helper method for toString impls

This is possibly already available in Maven core libs somewhere,
but I am not sure where to look. So into NarUtil it goes! :-)

Oneplus/nar-maven-plugin,Oneplus/nar-maven-plugin,maven-nar/nar-maven-plugin,dmakarov/nar-maven-plugin,dugilos/nar-maven-plugin,maven-nar/nar-maven-plugin,manu4linux/nar-maven-plugin,heathn/nar-maven-plugin,markjohndoyle/nar-maven-plugin,Oneplus/nar-maven-plugin,dmakarov/nar-maven-plugin,maven-nar/nar-maven-plugin,manu4linux/nar-maven-plugin,heathn/nar-maven-plugin,dugilos/nar-maven-plugin,eyalg1972/nar-maven-plugin,markjohndoyle/nar-maven-plugin,eyalg1972/nar-maven-plugin,dmakarov/nar-maven-plugin,maven-nar/nar-maven-plugin,Oneplus/nar-maven-plugin,Oneplus/nar-maven-plugin,heathn/nar-maven-plugin,manu4linux/nar-maven-plugin,dmakarov/nar-maven-plugin,dugilos/nar-maven-plugin,maven-nar/nar-maven-plugin,heathn/nar-maven-plugin,markjohndoyle/nar-maven-plugin,eyalg1972/nar-maven-plugin,manu4linux/nar-maven-plugin,dmakarov/nar-maven-plugin,eyalg1972/nar-maven-plugin,eyalg1972/nar-maven-plugin,dugilos/nar-maven-plugin,heathn/nar-maven-plugin,markjohndoyle/nar-maven-plugin,manu4linux/nar-maven-plugin,dugilos/nar-maven-plugin,markjohndoyle/nar-maven-plugin