Gateway overview scaffolding

[PavelJankoski]

Summary

Gateway overview scaffolding and new gateway overview header component.

Changes

• Refactor gateway connection component.
• Add placeholder divs for gateway overview panels.
• Create gateway overview header component.
• Add/Remove gateway bookmark.

Testing

Steps

1. Login to console.
2. Navigate to gateways page.
3. Select gateway.
4. Check the gateway overview page.

Results

Notes for Reviewers

This is still work in progress. Menu dropdown items should be updated in the header and small screen behaviour to be defined.

Checklist

• [x] Scope: The referenced issue is addressed, there are no unrelated changes.
• [x] 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.
• [x] Testing: The steps/process to test this feature are clearly explained including testing for regressions.
• [ ] Infrastructure: If infrastructural changes (e.g., new RPC, configuration) are needed, a separate issue is created in the infrastructural repositories.
• [x] Changelog: Significant features, behavior changes, deprecations and fixes are added to CHANGELOG.md.
• [x] Commits: Commit messages follow guidelines in CONTRIBUTING.md, there are no fixup commits left.