LP-558 accept case insensitive uav enum values

LP-558 accept case insensitive uav enum values

this is needed because TRUE/FALSE enum has been changed to True/False but old TRUE/FALSE is used by templates LP templates can be fixed but users' templates can't

logic is now to try case sensitive, if that fails try case insensitive if case insensitive works, a warning is logged

a new warning is also logged if the enum can't be found at all

LP-558 change TRUE/FALSE to True/False in all vehicle templates