This uses the BBS project name from the `Project` tab which could be
susceptible to upstream changes removing this feature.
The project_name template only works when you open a 3MF file. If you
create a new project and set the project name `Model.model_info` is
always null whether you save the project or not. If you save the current
project, switch to a new project/different project, then re-load it then
the template works as expected.
The plate number is assumed to always be <100 which matches the
formatting of the plate number in the UI.
Relates-To: https://github.com/SoftFever/OrcaSlicer/issues/3816
194ec6b1cd