Add Ability Learning Times

[exectails]

Back in the beta, and presumably for some time after, Abilities/Attributes were not only more expensive than they are now, many of them also took time to learn. You'd go to an NPC to learn them and they'd list a certain time span you needed to invest to learn any given ability. After you started learning one, you could then not learn any others until you were finished.

This feature appears to have been almost eradicated, since the current UI doesn't seem to have any handling for times. The client technically still "calculates" them, but they're all set to 0. While this is almost certainly not a highly sought after feature, and it shouldn't be high on our priority list, we might still want to implement it for preservation sake and customizability.

To implement it we'd need to do three things.

1. Reactivate and display the required times in the UI using client scripting
2. Delay leveling up an ability until the time passed
3. Lock learning new abilities until the previous one finished

But it's really low priority.

[felipecastagnarodecarvalho]

This would be a pretty annoying feature.
Not sure which is the plan for the content for the game but if we take in consideration the current late game content
and try to add this feature would be a pain to play the game since too much time wasted/waiting.

Another thing to consider is Skill/Ability Resets. Would the player have to wait again to learn the abilities for the new class?
Consider that changing the class are very common.

[exectails]

Keep in mind that this as far away from a Re:Build feature as you can get. Back then there was no class switching or simple and frequent resetting. It was also (presumably) removed because it is in fact an annoying mechanic. But it wouldn't feel right to me not to include it at all if we could do so with relatively little effort. Not to mention that it would be one more feature in the toolkit of the users. Who knows what interesting ideas they might have for it.