Service for setting a pose the robot will hold

[heuristicus]

Change Overview

Adds the /spot/posed_stand service which allows setting the body height and roll/pitch/yaw of the robot. The pose is unset when the robot starts walking. Could be merged into a single service with the set stand height service, but maybe good to have them separate.

Testing Done

Tested by sending poses close to joint limits of the robot. Sending a value above the joint limits is clamped to those limits.

[mhidalgo-rai]

@heuristicus how is this different from sending a stand robot command through the action interface? We have plenty of duplication across interfaces, would be good to motivate a service-based alternative.

[heuristicus]

I'm still getting familiar with the ros2 driver, by action interface do you mean sending things through the robot_command? If that's what you mean, I feel like the user experience for setting up commands with that mechanism was pretty involved to use. For some more complex commands I think using the robot command stuff is ok, since it's not really reasonable to add all the hundreds of commands the robot can run. I think it's good to have some which are commonly used be accessible so people can try things out more easily.

There's already a service for body height, and this is an expansion of that which uses the existing arguments the wrapper's stand function. I'd argue that this is more or less a "basic" command that is useful to access without having to run it through the robot command service.

[khughes-bdai]

I'm good with this change, since it seems like this is a simple enough command!

[tcappellari-bdai]

ya im good with this. I'll merge it in once its rebased on main