* Rename StartPlugin -> PluginRun
* Rename PluginRun.container -> PluginRun.containerImage
  This terminology is technically better as docker runs
  container _images_ in _containers_.
* Reset database (via name change) due to breaking
  change in migration files content.
  (This could be avoided, but no need for now.)
* Update v3 -> v4 because a rename is a breaking change