2 missing visual cues

[Pocus]

I think the interface can benefit from these:

- when only sneaky units are in a province, there is no visual cue on the map (the sole flag is the flag of the owner). Something like a smaller flag of your nation would be cool. I sometime forget about some scouts (yes nation overview can help me track them, but still)

- put level 4 search in all magic fields of the Capital, thats would be handy in the nation overview. Also many new players ask if they have to search their capital (two birds with one stone).