feat(state-representation): add utilities for CartesianStateVariable

[bpapaspyros]

Description

• Expose CartesianStateVariable utility functions and add stringify utilities #195

This PR solves the issue by making get_state_variable and set_state_variable public, and also adding two support functions to convert CartesianStateVariables from/to string.

Review guidelines

Estimated Time of Review: 5 minutes

Checklist before merging:

• Confirm that the relevant changelog(s) are up-to-date in case of any user-facing changes

[domire8]

Looks good, just one nitpick

[domire8]

Okay first part is done, now you also need to update the python bindings. Let me know if you need help with this

[domire8]

Nice

[bpapaspyros]

Nice

I noticed we didn't make the move to C++20 in control-libraries. Should we do that (in general)? Here or separate PR?

[domire8]

I noticed we didn't make the move to C++20 in control-libraries. Should we do that (in general)? Here or separate PR?

Not sure what that would imply. What would we gain from it?

You could also open a backlog issue to do the equivalent changes in JointState

[domire8]

Works for me

[bpapaspyros]

I noticed we didn't make the move to C++20 in control-libraries. Should we do that (in general)? Here or separate PR?

Not sure what that would imply. What would we gain from it?

at the moment nothing, it's not blocking. It's more for future proofing and to gain access to some more modern features that are always nice to have. (definitely not an immediate need)