Fix various issues via sentry

[kschiffer]

Summary

This quickfix PR addresses three minor issues that I've found via Sentry.

Changes

• Fix focusing form elements on error https://the-things-industries.sentry.io/issues/4722468009
• Account for end devices with empty session keys in the device general settings https://the-things-industries.sentry.io/issues/4722587543
• Account for unexpected responses from the device template converter https://the-things-industries.sentry.io/issues/4042370127

Testing

Manual testing and e2e

Notes for Reviewers

I'm not sure yet why the backend returns ABP end devices with empty session keys (maybe due to restricted rights)

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.
• The steps/process to test this feature are clearly explained including testing for regressions.
• 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.