feat(@angular/build): provide file dependencies map on compilation initialize result

[Deku-nattsu]

I am writing a rsbuild plugin that compiles angular, it uses the compilation classes underneath and thanks to the exposure of createAngularCompilation its been fairly smooth to implement.

however I’ve encountered a blocker when wiring up a dev server that correctly associates component TypeScript files with their html template resources. for this a dependency map is needed and that's what getResourceDependencies provides. but it isn’t publicly accessible from the compilation which is fair.

so right now, the only option seems to be creating a second Angular compiler instance in my plugin solely to access that API, which isn’t ideal. (i could be missing something?)

the PR change stores the dependencies map and returns it in initialization result which worked well in my case, but i am not sure if this is the right approach or what overhead it could introduce.

[clydin]

Thanks for the contribution.
Overall the change looks good.
Only concern, since this is an externally usable API, is the fileDependencies name. It may be overly broad of a term here since it's only the external resource files for the components in a given source file and not all the dependencies of a given file.