Add Thieves' Guilds counter to the Thieves' Guild window

[pazam-h2]

The Thieves’ Guild dialog reveals more information depending on how many Thieves’ Guilds the player owns, but the dialog itself does not currently show that number.

I suggest adding a small text line in the empty space above “Number of Towns:”, aligned with the existing category labels on the left side:

Owned Thieves’ Guilds: X

This would make it clearer to the player why some rankings are visible and others are hidden.

Obviously, it would not appear in the Oracle map-location dialog, since the Oracle is not based on the player’s owned Thieves’ Guild count.

related PR: #10832

[pazam-h2]

Closing, since the UI increase does not do anything for gameplay and is another thing to add to an already lengthy dialog box.