This reverts commit 1c26a4abb0c9e095b3f6ec9944c4b15f6f1cd064, reversing
changes made to 186824a568583d8f6f2a50501d940ed71608fa0b.
The changes broke plugin loading when using subcommands so these
changes will be reverted until the underlying issue can be
investigated and resolved.
* 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
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.
