Resource-specific cargo terminals (like Industries DLC warehouses, but for cargo terminals)

[originalfoo]

Based on comment on a TM:PE issue: https://github.com/CitiesSkylinesMods/TMPE/issues/141#issuecomment-506707402

Extending the idea:

• Option(s) on ship/train cargo terminal building info panel to choose what sort of resource(s) they accept
  • Similar to Industries DLC warehouses, but with multi-select rather than single select?
  • Example; I could create oil terminal, or grain + ore terminal, etc.
• Transfer Manager AI modded so it only considers cargo terminals with applicable resource type
  • If a terminal only accepts specific resource(s) in, then I assume any outgoing resource(s) will be same type(s)?
  • If so, we only really need to control what goes to, or is requested by, a terminal
• Would need 'Service Vehicle Selector' style mod to choose what type of ships/trains get spawned (both at terminal, and outside connection when bound for that terminal, if that's even possible?)

Main benefit here is realism/immersion. Currently I have oil being delivered to a cargo terminal filled with containers, then a container cargo ship collects it, ugh. Same grief when grain or ore goes to generic container terminal.

There's plenty of resource-specific vehicles in workshop, there's also "empty" ship/rail terminal assets, and obviously all the warehouses... would allow player to create much more realistic terminals for specific resource types.

[originalfoo]

AVO mod could potentially get option to define which resource(s) a ship/train can carry, in much the same way it has option to define "big truck" for cargo trucks (an integration with the No Big Trucks mod).

Trailer Variation Loader mod could potentially deal with trains, but how to ensure only relevant resources get put on trains at outside connections?

[originalfoo]

Example: Could create functional oil-only terminal:

Using Marine Oil Loading Arm prop to decorate a functional DIY Concrete Dock and oil tanker ships.

[originalfoo]

Example of problems with vanilla: This is a cargo rail terminal with grain silos, but it's getting truck deliveries of all sorts of non-grain resources, and there are non-grain trains visiting it.

Being able to define it as a "grain terminal" would limit trucks and trains (and/or ships, if it were a dock) to farming industry, which would greatly improve realism.