Fetch device from IS for Unclaim and GetClaimStatus RPCs

[KrishnaIyer]

Summary

References; https://github.com/TheThingsIndustries/product-management/issues/6

Changes

• Remove the request body from Unclaim. We are doing this since the support for a request body for HTTP Delete requests is unclear.
  • Also, we have to get the device from the IS to check that the EUIs are correct anyway.
  • This is a break in API but only the console/CLI currently use it and @adriansmares and I feel that this is justified.
• Get the EUIs for devices from the IS instead of using the request values for Unclaim and GetClaimStatus.
• Update tests
• Update console.

Testing

DCS locally tested. For the console part, I think if the Cypress tests pass, I think this is good.

Regressions

Will be tested on staging1 since there's currently no support for local TTJS testing.

Notes for Reviewers

⚠️ We are (mildly) breaking API here. The request URI for unclaim always needed to include the App and Device ID. It's just that we no longer accept a body.

Checklist

• Scope: The referenced issue is addressed, there are no unrelated changes.
• Compatibility: The changes are backwards compatible with existing API, storage, configuration and CLI, according to the compatibility commitments in README.md for the chosen target branch.
• Documentation: Relevant documentation is added or updated.
• Changelog: Significant features, behavior changes, deprecations and fixes are added to CHANGELOG.md.
• Commits: Commit messages follow guidelines in CONTRIBUTING.md, there are no fixup commits left.

[adriansmares]

We should remove that allow_delete_body from the proto generator as well.

[KrishnaIyer]

The console part is a "best effort". Let me know what else needs to be changed.

[johanstokking]

API and DCS LGTM

[kschiffer]

Codeowned LGTM.
Mildly related: #6333, but now we don't use any parameters here (other than route parameters) so it should be fine either way.

[nicholaspcr]

LGTM

[johanstokking]

• Also, we have to get the device from the IS to check that the EUIs are correct anyway.

As discussed offline; if the device does not exist, DCS should just proceed attempting to unclaim.

[KrishnaIyer]

I'll close this PR but keep the branch. I'll adapt some of these changes after #6381 is merged.