Add ecobot lidar map to office floor plan

[youliangtan]

Summary

This PR is to create a fleet_adapter_ecobot mock demo by using the existing office world. Hopefully, by referring to fleet_adapter_ecobot, users can learn how to write a custom rmf fleet adapter. The static transformation of the ecobot lidar map and rmf floorplan is calculated with traffic-editor.

• add ecobot's lidar map to office world floor plan on .building.yaml
• add a new launch file to show overlayed map with custom transformation via CLI:

ros2 launch rmf_demos office.launch.xml

# second terminal
ros2 launch rmf_demos map_server.launch.py map_name:=ecobot_office tx:=1.33 ty:=0.057 yaw:=-1.598

By running the map_server.launch.py, we can overlay the ecobot lidar map to the existing office floor plan (shown as below). This is helpful to check if the static transformation makes sense.

To run the demo with a mock `fleet_adapter_ecobot, please refer to the readme of this pr:
open-rmf/fleet_adapter_ecobot#1