Improve visualization of the maps

[koonpeng]

Moved over from open-rmf/rmf-web#137

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Since we agreed to have a sandbox for the tutorial, with a particular map (which could be the office map), I think it would be interesting to improve this map (make something similar to the airport maybe), because it will be displayed in all Romi-dashboard instances that future clients will have.
Current office blueprint:

Simulation map viewed from above

[Yadunund]

Migrated to open-rmf/rmf_demos#56