To persist some of its state, `ngcc` needs to update `package.json`
files (both in memory and on disk).
This refactoring abstracts these operations behind the
`PackageJsonUpdater` interface, making it easier to orchestrate them
from different contexts (e.g. when running tasks in parallel on multiple
processes).
Inspired by/Based on @alxhub's prototype: alxhub/angular@cb631bdb1
PR Close#32427
George Kalpakas