Replace popup for non-found strategy with panel entry

[mvl22]

Currently if a user loads a previously-planned route which does not have one or more strategy variations planned, this produces a popup for each such variation:

Sorry, the route for Quietest route could not be loaded: None of the desired plans were found.

(The latter part of this sentence is obviously badly-worded, incidentally.)

NB This scenario will always happen for instance with the old mobile site, which planned three separate routes rather than three at once.

We should replace this popup with writing into the route panel result.