When no heuristics match, still pick a fallback view if possible

As of https://github.com/rerun-io/rerun/pull/3323 our space view part systems now use indicator components to filter the heuristics. This means if we *just* log via the new `as_components` APIs, we don't get any views. Patching in indicators is still a bit painful, so it would be nice if we had sane fallback behavior.