Refetching of annotations when the logged-in user ID changes was
previously triggered by a complete reload of the `<sidebar-content>`
component via a `$route.reload()` call. This happened in response to a
`USER_CHANGED` event except for the first time that the profile was
fetched.

When using OAuth this broke because the test for whether this was the
first profile fetch or not was based on a change from null => non null
CSRF token (see `isInitialLoad` initialization). When using OAuth
however, there is no CSRF token.

This commit reworks refetching of annotations to remove the route
reloading and instead trigger it in the same way that it is triggered
when frames connect or disconnect, by calling
`SidebarContentController#loadAnnotations` when the logged-in userid
changes.