Patch 1.7.18: new placeable windows, Research balancing, bugfixes

- new windows added in Build Mode -> indoors -> windows
- fix TV show episodes after 1st episode showing as rank 0
- fix bug where double-clicking the Continue button in tutorial could skip a step and softlock the tutorial
- employees will now always reach task locations (desks, movie sets, tables) even if they are completely blocked by obstacles
- add Reset button in Product Creation for returning the planned product to default state
- TV shows category in product charts now shows all active shows (i.e. released and not retired) even they don't have all their episodes released yet
- the RP gain rate from Researchers has been adjusted and increases per decade, which should improve the Research pace, also the average RP gained per month is now shown in Research menu next to the player's current RP
- fix bug where tenant bubble popups of city houses were hidden when saving and loading while in city view, and were shown again only if you exit & re-enter city view
- save menu now stops the progressive loading of savegames list if the menu gets closed