refactor(@angular/cli): introduce new package manager abstraction #1963

Job	Run time
list	21s
workflow (build-cli)	1m 46s
workflow (devkit-core-tests)	1m 15s
workflow (build-unit-tests)	2m 29s
workflow (devkit-core-tests-rerun)	1m 30s
workflow (modules-builder-tests)	1m 43s
	9m 4s

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