Add "modernise city" action to the Construction Team and (maybe) the Settlers

Add to the Construction Team and (maybe) the Settlers the ability "modernise city" wich would instantly build in a city all the infrastructures that it would create in a funded city in expense of the unit. The option should appear when the unit is standing on the main plaza of the city.

PS: In addition to this I would suggest to make all infrastructures of earlier eras cheaper (-10% production cost) when going to the next era (it should be stackable, so when you are in the 3rd era you'll have a -10% on classical infrastructures and a -20% on the ancient era's ones)

PSS: [Here]'s a very similar idea; voting it shall raise the probability of actually seeing this suggestion included in the game. It would be a really nice saving-time addition.

Note: I kindly remind you that, since 1M pts ideas shall potentially make its addition to the game, an upvote would be really appreciated.

         Thank you for your support :)