Refactored the FE to have one data flow and local state management with RxAngular

The major change here is that all proposal and child objects are handled by the proposal service, which then provides an observable that everything watches for changes. Also, routes are much more specific than they used to be because the frontend now uses navigation between routes to clear unsaved data and keep forms from getting out of sync with Angular components.

In the middle layer, the CapabilityRequest API views have been changed to update CRPs instead of replacing them without deleting the old versions.