refactor(api): clarify APIError message usage and fix legacy lint error (#38012)

Avoid unclear & fragile "any" tricks, fix various abuses

Co-authored-by: wxiaoguang <wxiaoguang@gmail.com>

routers/api/v1/notify/user.go

@@ -134,7 +134,7 @@ func ReadNotifications(ctx *context.APIContext) {
 	if len(qLastRead) > 0 {
 		tmpLastRead, err := time.Parse(time.RFC3339, qLastRead)
 		if err != nil {
-			ctx.APIError(http.StatusBadRequest, err)
+			ctx.APIError(http.StatusBadRequest, err.Error())
 			return
 		}
 		if !tmpLastRead.IsZero() {