These changes implement `GetRequiredPlugins` for Go using a registry
mechanism and an alternate entry point for `pulumi.Run`. Packages that
require plugins are expected to register themselves with the Pulumi SDK.
When `pulumi.Run` is used and the `PULUMI_PLUGINS` envvar is truthy, the
program will dump a JSON-encoded description of its required plugins to
stdout. The language host then uses this description to respond to
`GetRequiredPlugins`.
- Make go comment generation lint-clean for blank comment lines
- Fix the casing of `Provider.py` in Python to `provider.py`
- Fix a spacing issue in the NodeJS code generator
The schema format is described in pkg/codegen/schema/schema.go. The code
generators are derived from the code generators contained in
https://github.com/pulumi/pulumi-terraform-bridge/pkg/tfgen, with the
exception of the Go code generator, which is net new.
