Support nullable hardware attributes on Ponos agents

https://redmine.teklia.com/issues/5075

Requires enterprise#28

The Ponos TypeScript types for agents should be updated to reflect the changes made in backend#1733 (closed). To make the null values easier to handle in components, a union of a type with mode: "slurm" and null values with a type with mode: "docker" and non-null values for the hardware attributes should be used.

The InLineAgent component should be updated to support the missing hardware attributes. The RAM and CPU section should be blank, displaying a em-dash — like what the GPU section already does when there are no GPUs.