Missing user meta in OSS event

[ionling]

fc-runtime-go-sdk/events/oss.go

Line 43 in 3c934e3

type ObjectMeta struct {

ObjectMeta has only one field, which is not always sufficient.

I suggest the following changes:

type ObjectMeta struct {
	MimeType *string           `json:"mimeType"`
	UserMeta map[string]string `json:"userMeta"`
}