The package `github.com/golang/protobuf/proto` is deprecated in favor
`google.golang.org/protobuf/proto`. We should update the codes to
recommended package.
Signed-off-by: Icarus Wu <icaruswu66@qq.com>
This adds a tools.go file to import all command packages used for
go:generate. Doing so makes it possible to execute go-based code
generators using 'go run', locking in the tool version using go.mod.
Co-authored-by: Felix Lange <fjl@twurst.com>
