Add extra field to model instance (#14203)

### What problem does this PR solve?

Now each model support region with different URL

### Type of change

- [x] New Feature (non-breaking change which adds functionality)

---------

Signed-off-by: Jin Hai <haijin.chn@gmail.com>

internal/entity/tenant_model_instance.go

@@ -23,6 +23,7 @@ type TenantModelInstance struct {
 	ProviderID   string `gorm:"column:provider_id;size:32;not null;uniqueIndex:idx_api_key_provider_id" json:"provider_id"`
 	APIKey       string `gorm:"column:api_key;size:512;not null;uniqueIndex:idx_api_key_provider_id" json:"api_key"`
 	Status       string `gorm:"column:status;size:32;default:'active'" json:"status"`
+	Extra        string `gorm:"column:extra;size:512;default:'active'" json:"extra"`
 	BaseModel
 }