Refactor codebase, introduce relaymode package, update constants and improve consistency

- Refactor constant definitions and organization
- Clean up package level variables and functions
- Introduce new `relaymode` and `apitype` packages for constant definitions
- Refactor and simplify code in several packages including `openai`, `relay/channel/baidu`, `relay/util`, `relay/controller`, `relay/channeltype`
- Add helper functions in `relay/channeltype` package to convert channel type constants to corresponding API type constants
- Remove deprecated functions such as `ResponseText2Usage` from `relay/channel/openai/helper.go`
- Modify code in `relay/util/validation.go` and related files to use new `validator.ValidateTextRequest` function
- Rename `util` package to `relaymode` and update related imports in several packages

model/main.go

@@ -12,6 +12,7 @@ import (
 	"github.com/songquanpeng/one-api/common/env"
 	"github.com/songquanpeng/one-api/common/helper"
 	"github.com/songquanpeng/one-api/common/logger"
+	"github.com/songquanpeng/one-api/common/random"
 	"gorm.io/driver/mysql"
 	"gorm.io/driver/postgres"
 	"gorm.io/driver/sqlite"
@@ -33,10 +34,10 @@ func CreateRootAccountIfNeed() error {
 		rootUser := User{
 			Username:    "root",
 			Password:    hashedPassword,
-			Role:        common.RoleRootUser,
-			Status:      common.UserStatusEnabled,
+			Role:        RoleRootUser,
+			Status:      UserStatusEnabled,
 			DisplayName: "Root User",
-			AccessToken: helper.GetUUID(),
+			AccessToken: random.GetUUID(),
 			Quota:       500000000000000,
 		}
 		DB.Create(&rootUser)
@@ -46,7 +47,7 @@ func CreateRootAccountIfNeed() error {
 				Id:             1,
 				UserId:         rootUser.Id,
 				Key:            config.InitialRootToken,
-				Status:         common.TokenStatusEnabled,
+				Status:         TokenStatusEnabled,
 				Name:           "Initial Root Token",
 				CreatedTime:    helper.GetTimestamp(),
 				AccessedTime:   helper.GetTimestamp(),