Implemented Akkad and Assyria siege auras

[O-spin]

Also removed the global modifier for Akkadian units vs cities.

Assyrian siege tower changes copied from BNW mod.

[SeventhM]

Late response, sorry, needed to double check a few stuff. If I need to I'll probably boot up Civ 5 to really make sure I haven't gone crazy, but my opinion here *should* be accurate

Akkad change is fine (I suspect this is actually due to a change in some patch, but not currently in a mood to go digging. It doesn't really matter anyways). However, I do need to double check if there's a weird edge case here in Unciv that I never thought of. Though... me thinking out loud, not relevant here

Assyria change... I don't understand the goal. You gain the promotion by moving but lose it........... on turn end. Why not just lose it on moving as well? I don't understand why it is lost on turn end, except to remove it for upgrades. But I'm pretty sure you can remove promotions during the unit upgrade in like, 2 or 3 different ways, and that's before me going and checking

And if it's supposed to be gained on move and goes away on move... Why is it a on move promotion at all? Why not have it as a unique on the unit itself?

[O-spin]

I'll wait with changing the PR, currently trying to get some changes into unciv that would make both these bonuses work better (modifiers stacking and "other" mapunit scope).

[O-spin]

Why not have it as a unique on the unit itself?

If possible I also prefer having the bonus on the unit itself rather than on a promotion, don't remember what the problem was rn