Bug#1141546: node-rollup-plugin-virtual ready for review/sponsoring

[Juan M . Méndez Rey]

https://salsa.debian.org/mendezr/node-rollup-plugin-virtual/

This is needed by node-lit so it can be reproducible and can migrate to 
testing, and transitively it will allow siso to migrate to testing too.

Please, have a look.

Best,
Juan