fix(server): aggregate Kura usage by region

Summary

• Aggregate Kura usage traffic by region instead of individual Kura pod/node ids.
• Update the Usage dashboard table copy, row keys, and async assign names to reflect the region-level breakdown.
• Refresh the dashboard usage gettext template and tests for region rollups.

Current setup

Testing

• mix format --check-formatted lib/tuist/kura/usage.ex lib/tuist_web/live/usage_live.ex lib/tuist_web/live/usage_live.html.heex test/tuist/kura/usage_test.exs test/tuist_web/live/usage_live_test.exs
• TUIST_SERVER_CLICKHOUSE_HTTP_PORT=28123 TUIST_SERVER_TEST_CLICKHOUSE_DB=tuist_test_usage_28123 mix test test/tuist/kura/usage_test.exs test/tuist_web/live/usage_live_test.exs
• TUIST_ENABLE_CACHING=1 TUIST_FEATURE_FLAG_KURA=1 tuist cache warm ProjectDescription