These changes address the following warning showing up on `go get`
operations:
go: module github.com/golang/protobuf is deprecated: Use the
"google.golang.org/protobuf" module instead.
All changes are made using the recommendations in the per-function
deprecation notices from the docs at
https://pkg.go.dev/github.com/golang/protobuf/ptypes
* Populates ComponentOptions into plugin structs
* Maps options for legacy Provider Plugins into PluginOptions
* Demos use of PluginOptions in a stub provider
* Honors plugin priority and defaultable settings
- Pulls in the SDK changes to Project.DefaultProvider and Project.Target
- Implements the hefty default provider method
- Un-hard-codes provider from Target, and sets it when a Target is
looked up from a Project
* Populate push configs when parsing the vagrantfile
* Allow untyped configs to be shipped over GRPC
* In our demo plugin, walk the vagrantfile and snag the config
Example Vagrantfile that works with the demo plugin:
```ruby
Vagrant.configure("2") do |config|
config.push.define "myplugin" do |push|
push.coolkey = "coolvalue"
push.alist = ["so", "many", "items"]
push.ahash = { "hashkey" => "hashvalue" }
end
end
```
This uses the new Push plugin support added to the plugin SDK in https://github.com/hashicorp/vagrant-plugin-sdk/pull/106 to make the following changes:
* The plugin manager on the Go side now registers push plugins
* The the _remote_ plugin manager on the Ruby side now calls over to
the go side to get push plugins
* All the wiring is hooked up such that when a push plugin is replaced
with its remote GRPC-client-wielding equivalent, the messages are
ferried around.
