This patch is split off from D2863. It introduces a mace champion swordsman, using the black cloak actor, trainable at fortress and (with technology) barracks. This gives mace a much needed counter vs rams (athen has marines and spart skiritai).
While at it, it also renames `maur_champion_maiden_barracks.xml` to `maur_champion_infantry_swordsman_barracks.xml` because it's functionally identical to the new mace champion and there is no point in having two lines in the barracks template instead of one.
The Thracian black cloak is historically justifiable as a Macedonian champion: Philip V of Macedon (r. 221โ179 BC) had an elite unit of Thracians equipped with rhomphaia, black cloaks, and white shields, serving as a vanguard (Plutarch //Aemilius Paulus// 18.3).