refactor(@ngtools/webpack): support optional baseUrl with tsconfig paths #2794

Job	Run time
build-e2e-windows	26s
build	30s
lint	1m 55s
e2e-windows	0s
publish-snapshots	0s
test	-1s
Browser Compatibility Tests	-1s
e2e	-1s
e2e-snapshots	-1s
e2e-package-managers	-1s
	2m 46s

Provide feedback