Context

• We think that having two very different i18n behaviors across 2.7.x and the latest LTS is going to be a source of quality risk
• We want all supported versions to use i18n in the same way

In scope

• Move i18n into a plugin and distribute with blue ocean
• Resource bundles should be cached appropriately
  • /_i18n/resource/blueocean-dashboard/1.0.0/jenkins.plugins.blueocean.dashboard.Messages/en
  • /_i18n/resource/$PLUGIN_NAME/$PLUGIN_VERSION/$BUNDLE_NAME/$LANG
  • Any non-snapshot version should be cached for 365 days
  • Any snapshot version should not be cached
• Update blueocean i18n so that it loads via the new endpoint above
• Remove any english fall backs from the jsx as now all versions of Blue Ocean can load i18n bundles
• Locale spec ala JENKINS-39034