Streamline group creation with vehicle creation

[DeletedUser23]

Groups are great for managing bus and train lines, but tedious to create. Since groups let duplicate vehicles share name, I thought the Rename button (pencil icon) in the vehicle viewport window could be the key to easy group creation. I have 2 alternative proposals :

• Make shift-clicking Rename rename the group instead of the vehicle. If the vehicle does not belong to a group, automatically create a group for that vehicle.
• In the Rename window, add a button Create group to create a group of the given name containing the vehicle.

Also, since many buttons in OpenTTD can be control-clicked to affect vehicles with shared orders, I think control-clicking Rename should rename or reset the name of linked vehicles too. With my first proposal, control-shift-clicking Rename would create a group and add all the linked vehicles to the new group.

[splungedude]

In the list of vehicles that share orders there is the option to create a group from that list. This somewhat simplifies the group creation process. I agree that easier access to the (re)naming of groups would be nice to have.

[DeletedUser23]

I looked at the code and this did not look too hard to implement. I have opened a pull request:
https://github.com/OpenTTD/OpenTTD/pull/10849