Contain failure to activate a fragment.

Failing to activate a fragment should result in that fragment failing to activate, not the portal experience completely failing.

In response new adopter issue [reported on uportal-user@](https://lists.wisc.edu/read/messages?id=33030191#33030191).

I'll be the first to admit this fix may not be good enough and we really need to surface the error to the user because while this fix will allow them to have a degraded portal experience, it's a degraded experience missing some content they were intended to enjoy, and it's potentially a *very* or *unusably* degraded experience depending on what the missing fragments are (regions?).