Add a WaitUntil event and use it for ResponsiveWait

[mxgrey]

This PR adds a WaitUntil event and uses it at the end of each ResponsiveWait cycle. This will relieve system integrators of the need to wait until the last waypoint's time before triggering the path_finished_callback of RobotCommandHandle::follow_new_path. Now system integrators can just trigger that callback as soon as the robot arrives at the end of the path.

[codecov]

Codecov Report

Merging #199 (1ff4997) into main (b5557fa) will increase coverage by 0.08%.
The diff coverage is n/a.

@@            Coverage Diff             @@
##             main     #199      +/-   ##
==========================================
+ Coverage   17.83%   17.91%   +0.08%     
==========================================
  Files         418      840     +422     
  Lines       38370    77208   +38838     
  Branches    18376    36996   +18620     
==========================================
+ Hits         6842    13834    +6992     
- Misses      24203    48533   +24330     
- Partials     7325    14841    +7516     

Flag	Coverage Δ
tests	17.91% <ø> (+0.08%)	⬆️

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Impacted Files	Coverage Δ
...src/rmf_fleet_adapter/jobs/detail/impl_Rollout.hpp
..._ros2/src/rmf_traffic_ros2/schedule/YamlLogger.cpp
...task_ros2/src/rmf_task_ros2/bidding/Auctioneer.cpp
...-4.1.0/Rx/v2/src/rxcpp/operators/rx-take_until.hpp
..._ros2/rmf_fleet_adapter/test/dump_fleet_states.cpp
...f_fleet_adapter/agv/internal_RobotUpdateHandle.hpp
...raffic_ros2/test/unit/test_ParticipantRegistry.cpp
...adapter/include/rmf_fleet_adapter/agv/Waypoint.hpp
...3n/rmf_ros2/rmf_task_ros2/src/mock_bidder/main.cpp
...eet_adapter/src/rmf_fleet_adapter/tasks/Patrol.cpp
... and 1248 more

[aaronchongth]

Thanks for adding this so quickly! LGTM