refactor(@angular-devkit/schematics): support `isolatedDeclarations` … #1563

Job	Run time
list	30s
workflow (devkit-core-tests-rerun)	25s
workflow (devkit-core-tests)	27s
workflow (build-cli)	26s
workflow (build-unit-tests)	28s
workflow (modules-builder-tests)	25s
	2m 41s

Provide feedback