Remove racks and row labels in cluster graphical representation

[rezib]

Rows and racks labels don't bring real values in this context and they need too much vertical spacing when large infrastructure have to be represented. They should be removed from these graphical representation to save some spacing.

[rezib]

This requires these features in RacksDB:

• Drawing parameter to remove racks labels in infrastructures RacksDB#89
• Drawing parameter to remove row labels in infrastructures RacksDB#90

A new release of RacksDB v0.5.0 must be published to benefit from these features. Then, a fix can be implemented in Slurm-web to use these new drawing parameters.