Previously, ngtsc would resolve forward references while evaluating the
bootstrap, declaration, imports, and exports fields of NgModule types.
However, when generating the resulting ngModuleDef, the forward nature of
these references was not taken into consideration, and so the generated JS
code would incorrectly reference types not yet declared.
This commit fixes this issue by introducing function closures in the
NgModuleDef type, similarly to how NgComponentDef uses them for forward
declarations of its directives and pipes arrays. ngtsc will then generate
closures when required, and the runtime will unwrap them if present.
PR Close#29198