- Add network switcher.
- Explorer landing page with light stats:
- summary of recent messages per chain.
- shows most recent messages, polls for updates.
- chain-details view.
- super basic message details view: json.
- runs in devnet.
- add network switcher to guardian-list page.
- links to native explorers (etherscan, etc.)
- polygon support
- animations when data updates
Change-Id: I26616afab551a7555421a45dee9f016beecbf93e