Support batch task submissions

[koonpeng]

Feature request

Although multiple tasks can be submitted programatically, it does not provide proper consistency when one or more of the tasks:

• have invalid inputs
• failed for any other reasons (e.g. network connections etc)

Often it is desired for either all or none of the tasks to be started.

Also addresses open-rmf/rmf-web#484.

Description

Implementation considerations

Alternatives

Additional information

[Yadunund]

The feature will need to be implemented in the ROS 2 dispatcher node followed by suitable changes within the fleet adapter. I've opened a ticket for this open-rmf/rmf_ros2#115