[Dashing/Eloquent] List keys doesn't list nested keys

[ivanpauno]

Bug report

Required Info:

• Operating System:
  • Ubuntu 18.04 (should happen in any)
• Installation type:
  • from source (should happen in any)
• Version or commit hash:
  • master
• DDS implementation:
  • N/A
• Client library (if applicable):
  • N/A

Steps to reproduce issue

ros2 security generate_artifacts -k tmp -n /node1 /ns/node1 /ns/node2
ros2 security list_keys tmp

Expected behavior

Output:

/node1
/ns/node1
/ns/node2

Actual behavior

Output:

node1
ns

Additional information

This should be fixed for Dashing/Eloquent, and also for Foxy after #177 is merged.
Add a regression test too.

[hidmic]

@ros2/security_working_group are you planning to take a stab at this one in the near term e.g. before Foxy feature freeze?

[kyrofa]

Do the still-in-flux design updates impact this at all?

[ivanpauno]

Do the still-in-flux design updates impact this at all?

The fixes for Dashing and Eloquent aren't blocked by those changes.
About Foxy, maybe contexts folder is renamed to enclaves, but it isn't a big deal to update the folder name in a follow up.

[ivanpauno]

Reopening to track the fix for Dashing/Eloquent

[mikaelarguedas]

Backported and released
Dashing: #223 ros/rosdistro#25499
Eloquent: #222 ros/rosdistro#25492