Add object count for every plate or selected objects

[VDechev]

Hello, recently I started printing a lot of small models and it was hard to keep how many of them are on the plate.

I would love to see something similar to Windows where it shows how many files are selected(in our case 3d models)

Another similar idea suggestion is to add the object count somewhere next to each plate

[rkarlsba]

I'd voach for this! I'm also with a current project with >200 objects, but I have no idea of how many there are in total or per plate, since there is no counter. Please add this - it shouldn't be hard.