Mark Component::Clone as const

[mjcarroll]

Split from #1249. Mark Clone method as const.

This is likely not back-portable as it breaks API. Any components that implement a custom Clone will fail to compile. There are none in the main ign-gazebo codebase, but there is a possibility of external users doing so.

Signed-off-by: Michael Carroll [email protected]

[chapulina]

LGTM. It may be worth dropping a note on the migration guide.

[codecov]

Codecov Report

Merging #1300 (c08215d) into main (cfb83a2) will decrease coverage by 0.01%.
The diff coverage is 100.00%.

@@            Coverage Diff             @@
##             main    #1300      +/-   ##
==========================================
- Coverage   62.02%   62.01%   -0.02%     
==========================================
  Files         276      276              
  Lines       23030    23020      -10     
==========================================
- Hits        14285    14276       -9     
+ Misses       8745     8744       -1     

Impacted Files	Coverage Δ
include/ignition/gazebo/components/Component.hh	100.00% <100.00%> (ø)
src/systems/air_pressure/AirPressure.cc	73.23% <100.00%> (-0.74%)	⬇️
src/systems/altimeter/Altimeter.cc	73.97% <100.00%> (-0.70%)	⬇️
src/systems/force_torque/ForceTorque.cc	73.72% <100.00%> (ø)
src/systems/imu/Imu.cc	72.61% <100.00%> (-0.64%)	⬇️
src/systems/logical_camera/LogicalCamera.cc	75.64% <100.00%> (-0.61%)	⬇️
src/systems/magnetometer/Magnetometer.cc	70.88% <100.00%> (-0.72%)	⬇️
src/Server.cc	86.74% <0.00%> (+0.60%)	⬆️

---

Continue to review full report at Codecov.

Legend - Click here to learn more
Δ = absolute <relative> (impact), ø = not affected, ? = missing data
Powered by Codecov. Last update 892c296...c08215d. Read the comment docs.

[mjcarroll]

It may be worth dropping a note on the migration guide.

73d213b

[mjcarroll]

@osrf-jenkins retest this please