feat: support gpt-4o (songquanpeng#1431)

Author: WqyJh

relay/adaptor/openai/constants.go

@@ -7,6 +7,7 @@ var ModelList = []string{
 	"gpt-4", "gpt-4-0314", "gpt-4-0613", "gpt-4-1106-preview", "gpt-4-0125-preview",
 	"gpt-4-32k", "gpt-4-32k-0314", "gpt-4-32k-0613",
 	"gpt-4-turbo-preview", "gpt-4-turbo", "gpt-4-turbo-2024-04-09",
+	"gpt-4o", "gpt-4o-2024-05-13",
 	"gpt-4-vision-preview",
 	"text-embedding-ada-002", "text-embedding-3-small", "text-embedding-3-large",
 	"text-curie-001", "text-babbage-001", "text-ada-001", "text-davinci-002", "text-davinci-003",

relay/billing/ratio/model.go

@@ -32,6 +32,8 @@ var ModelRatio = map[string]float64{
 	"gpt-4-turbo-preview":     5,    // $0.01 / 1K tokens
 	"gpt-4-turbo":             5,    // $0.01 / 1K tokens
 	"gpt-4-turbo-2024-04-09":  5,    // $0.01 / 1K tokens
+	"gpt-4o":                  2.5,  // $0.005 / 1K tokens
+	"gpt-4o-2024-05-13":       2.5,  // $0.005 / 1K tokens
 	"gpt-4-vision-preview":    5,    // $0.01 / 1K tokens
 	"gpt-3.5-turbo":           0.25, // $0.0005 / 1K tokens
 	"gpt-3.5-turbo-0301":      0.75,
@@ -280,7 +282,9 @@ func GetCompletionRatio(name string) float64 {
 		return 4.0 / 3.0
 	}
 	if strings.HasPrefix(name, "gpt-4") {
-		if strings.HasPrefix(name, "gpt-4-turbo") || strings.HasSuffix(name, "preview") {
+		if strings.HasPrefix(name, "gpt-4-turbo") ||
+			strings.HasPrefix(name, "gpt-4o") ||
+			strings.HasSuffix(name, "preview") {
 			return 3
 		}
 		return 2