Switch to googleapi.Error?

[vtopc]

https://pkg.go.dev/google.golang.org/api/googleapi#Error:

type Error struct {
	// Code is the HTTP response status code and will always be populated.
	Code [int](https://pkg.go.dev/builtin#int) `json:"code"`
	// Message is the server response message and is only populated when
	// explicitly referenced by the JSON server response.
	Message [string](https://pkg.go.dev/builtin#string) `json:"message"`
	// Details provide more context to an error.
	Details []interface{} `json:"details"`
	// Body is the raw response returned by the server.
	// It is often but not always JSON, depending on how the request fails.
	Body [string](https://pkg.go.dev/builtin#string)
	// Header contains the response header fields from the server.
	Header [http](https://pkg.go.dev/net/http).[Header](https://pkg.go.dev/net/http#Header)

	Errors [][ErrorItem](https://pkg.go.dev/google.golang.org/api/googleapi#ErrorItem)
	// contains filtered or unexported fields
}