TL;DRAllow sending trains to specific train stops when multiple stops with the same name exist.
What ?When sending a train to a station the game goes through all the train stops with the right name and picks one to send the train to. Allow passing the ID of the train stop to go to as optional argument. If the given train stop is enabled, reachable and has not reached it's train limit then it is used as destination of the train. On success the train ID is returned or nil.
Optional add a third argument "fail :: bool". If fail is true the call will return nil when the given station is not suitable. If fail is false then the given station is only taken as a suggestion and the normal algorithm is used when unsuitable.
Why ?When enhancing the train experience to allow more dynamic schedules it often is desirable to pick the train stop based on criteria other than the path cost. And then mod wants the train to go to specific stations but the game does not allow directing the train that specifically.
Note: As a workaround mods can insert a temporary train stop to send the train to a specific rail tile (that of the train stop) and then the train stop has a path cost of 0 and will be picked. Usually that is. Not so if the train comes from the wrong direction since temporary train stops don't have a direction and the wrong direction (for the train stop) might be cheaper. Using a temporary train stop also hides which stop the train is targeting in the train overview. So overall not the ideal solution.
This request would allow mods to properly send trains to where they are supposed to go according to the mods logic.