feat: Introduce settings package and refactor constants

- Added a new `setting` package to replace the `constant` package for configuration management, improving code organization and clarity.
- Moved various configuration variables such as `ServerAddress`, `PayAddress`, and `SensitiveWords` to the new `setting` package.
- Updated references throughout the codebase to use the new `setting` package, ensuring consistent access to configuration values.
- Introduced new files for managing chat settings and midjourney settings, enhancing modularity and maintainability of the code.

setting/chat.go

@@ -0,0 +1,35 @@
+package setting
+
+import (
+	"encoding/json"
+	"one-api/common"
+)
+
+var Chats = []map[string]string{
+	{
+		"ChatGPT Next Web 官方示例": "https://app.nextchat.dev/#/?settings={\"key\":\"{key}\",\"url\":\"{address}\"}",
+	},
+	{
+		"Lobe Chat 官方示例": "https://chat-preview.lobehub.com/?settings={\"keyVaults\":{\"openai\":{\"apiKey\":\"{key}\",\"baseURL\":\"{address}/v1\"}}}",
+	},
+	{
+		"AMA 问天": "ama://set-api-key?server={address}&key={key}",
+	},
+	{
+		"OpenCat": "opencat://team/join?domain={address}&token={key}",
+	},
+}
+
+func UpdateChatsByJsonString(jsonString string) error {
+	Chats = make([]map[string]string, 0)
+	return json.Unmarshal([]byte(jsonString), &Chats)
+}
+
+func Chats2JsonString() string {
+	jsonBytes, err := json.Marshal(Chats)
+	if err != nil {
+		common.SysError("error marshalling chats: " + err.Error())
+		return "[]"
+	}
+	return string(jsonBytes)
+}