perf(ngcc): read dependencies from entry-point manifest (#36486)

Previously, even if an entry-point did not need to be processed,
ngcc would always parse the files of the entry-point to compute
its dependencies. This can take a lot of time for large node_modules.

Now these dependencies are cached in the entry-point manifest,
and read from there rather than computing them every time.

See https://github.com/angular/angular/issues/36414\#issuecomment-608401834
FW-2047

PR Close #36486

packages/compiler-cli/ngcc/test/integration/ngcc_spec.ts

@@ -1107,7 +1107,12 @@ runInEachFileSystem(() => {
         // had removed earlier.
         manifest = JSON.parse(fs.readFile(_('/node_modules/__ngcc_entry_points__.json')));
         expect(manifest.entryPointPaths).toContain([
-          _('/node_modules/@angular/common'), _('/node_modules/@angular/common/testing')
+          _('/node_modules/@angular/common'), _('/node_modules/@angular/common/testing'),
+          [
+            _('/node_modules/@angular/core'), _('/node_modules/@angular/common'),
+            _('/node_modules/rxjs')
+          ],
+          [], []
         ]);
       });
     });