This commit fixes ngtsc's import generator to use the ReflectionHost when
looking through the exports of an ES module to find the export of a
particular declaration that's being imported. This is necessary because
some module formats like CommonJS have unusual export mechanics, and the
normal TypeScript ts.TypeChecker does not understand them.
This fixes an issue with ngcc + CommonJS where exports were not being
enumerated correctly.
FW-1630 #resolve
PR Close#33192