Feat: support database charset option and more DMBS driver

pkg/conf/conf.go

@@ -16,6 +16,7 @@ type database struct {
 	TablePrefix string
 	DBFile      string
 	Port        int
+	Charset     string
 }
 
 // system 系统通用配置

pkg/conf/defaults.go

@@ -12,9 +12,10 @@ var RedisConfig = &redis{
 
 // DatabaseConfig 数据库配置
 var DatabaseConfig = &database{
-	Type:   "UNSET",
-	DBFile: "cloudreve.db",
-	Port:   3306,
+	Type:    "UNSET",
+	Charset: "utf8",
+	DBFile:  "cloudreve.db",
+	Port:    3306,
 }
 
 // SystemConfig 系统公用配置
@@ -68,5 +69,5 @@ var SSLConfig = &ssl{
 }
 
 var UnixConfig = &unix{
-    Listen: "",
+	Listen: "",
 }