Addresses concerns raised in discussion here https://github.com/hashicorp/vagrant-ruby/pull/219#discussion_r816966056 and makes it so we don't have to change any plugin code to make things work. Depends on https://github.com/hashicorp/vagrant-plugin-sdk/pull/133
Vagrant Core Plugins
These are plugins that ship with Vagrant. Vagrant core uses its own plugin system to power a lot of the core pieces that ship with Vagrant. Each plugin will have its own README which explains its specific role.
Generate proto
grpc_tools_ruby_protoc -I . --ruby_out=gen/plugin --grpc_out=gen/plugin ./plugin_server.proto