changeweather command does not report an error when entering non-existent region

OpenMW Revision: 1ffa02b2

Vanilla: Steam, with Tribunal and Bloodmoon and no mods.

Vanilla behavior is to report an error if you use the changeweather command with a non-existent region:

OpenMW does not report an error, the command silently fails:

Not reporting an error can be particularly confusing with the changeweather command. This is because most results on the changeweather command on google, in fact all results that i found while trying to use it, leave out the need to include "region" in the region name.

While the most important issue is just to report an error, it would also be nice if the game would notice and give a hint if the player omits "region". e.g. If the player writes "West Gash" instead of "West Gash Region", OpenMW could give a hint along the lines of Did you mean "West Gash Region"?. This probably doesn't need to be more sophisticated than checking if region_name + " Region" exists