bgpd, lib: Include SID structure in seg6local nexthop (backport #16835)

[mergify]

Include SID structure information when installing/removing an SRv6 SID in/from the forwarding plane.

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This is an automatic backport of pull request #16835 done by Mergify.

[mergify]

Cherry-pick of a764fb9 has failed:

On branch mergify/bp/stable/10.1/pr-16835
Your branch is ahead of 'origin/stable/10.1' by 3 commits.
  (use "git push" to publish your local commits)

You are currently cherry-picking commit a764fb9bd8.
  (fix conflicts and run "git cherry-pick --continue")
  (use "git cherry-pick --skip" to skip this patch)
  (use "git cherry-pick --abort" to cancel the cherry-pick operation)

Unmerged paths:
  (use "git add <file>..." to mark resolution)
	both modified:   bgpd/bgp_mplsvpn.c

no changes added to commit (use "git add" and/or "git commit -a")

Cherry-pick of 1587169 has failed:

On branch mergify/bp/stable/10.1/pr-16835
Your branch is ahead of 'origin/stable/10.1' by 4 commits.
  (use "git push" to publish your local commits)

You are currently cherry-picking commit 1587169214.
  (fix conflicts and run "git cherry-pick --continue")
  (use "git cherry-pick --skip" to skip this patch)
  (use "git cherry-pick --abort" to cancel the cherry-pick operation)

Unmerged paths:
  (use "git add <file>..." to mark resolution)
	both modified:   bgpd/bgp_mplsvpn.c

no changes added to commit (use "git add" and/or "git commit -a")

To fix up this pull request, you can check it out locally. See documentation: https://docs.github.com/en/pull-requests/collaborating-with-pull-requests/reviewing-changes-in-pull-requests/checking-out-pull-requests-locally