Replace rclcpp::Rate with rclcpp::WallRate

[onionsflying]

Description

rclcpp::WallRate is preferable to rclcpp::Rate, because with rclcpp::WallRate rate.sleep() won’t stall due to backward system clock adjustments (e.g., a one-day rollback).

[github-actions]

This PR is stale because it has been open for 45 days with no activity. Please tag a maintainer for help on completing this PR, or close it if you think it has become obsolete.

[EzraBrooks]

seems right to me

[codecov]

Codecov Report

❌ Patch coverage is 25.00000% with 3 lines in your changes missing coverage. Please review.
✅ Project coverage is 46.18%. Comparing base (b22cae3) to head (13110f8).
⚠️ Report is 1 commits behind head on main.

Files with missing lines	Patch %	Lines
...c/default_capabilities/tf_publisher_capability.cpp	0.00%	1 Missing ⚠️
...nitor/src/trajectory_monitor_middleware_handle.cpp	0.00%	1 Missing ⚠️
moveit_ros/warehouse/src/broadcast.cpp	0.00%	1 Missing ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #3558      +/-   ##
==========================================
- Coverage   46.19%   46.18%   -0.00%     
==========================================
  Files         720      720              
  Lines       59179    59179              
  Branches     7595     7595              
==========================================
- Hits        27331    27326       -5     
- Misses      31681    31687       +6     
+ Partials      167      166       -1     

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