fix(editor): check parent MIME types to support subtype files in isMimeTypeSupport

- Retain QMimeType object to enable parent type lookup
- Add parentMimeTypes() fallback to match subtypes against whitelist

修复(editor): 在 isMimeTypeSupport 中检查父 MIME 类型以支持子类型文件打开

Log: 通过父 MIME 类型继承关系扩展白名单匹配范围，修复子类型文件无法打开的问题
Bug: https://pms.uniontech.com/bug-view-362023.html

Author: zhangjiarui

src/common/utils.cpp

@@ -1,4 +1,4 @@
-// SPDX-FileCopyrightText: 2011-2023 UnionTech Software Technology Co., Ltd.
+// SPDX-FileCopyrightText: 2011-2026 UnionTech Software Technology Co., Ltd.
 //
 // SPDX-License-Identifier: GPL-3.0-or-later
 
@@ -539,6 +539,7 @@ bool Utils::isMimeTypeSupport(const QString &filepath)
     textMimeTypes << "application/cmd"
                   << "application/javascript"
                   << "application/json"
+                  << "application/schema+json"
                   << "application/pkix-cert"
                   << "application/octet-stream"
                   << "application/sql"
@@ -564,6 +565,7 @@ bool Utils::isMimeTypeSupport(const QString &filepath)
                   << "application/x-yaml"
                   << "application/x-pem-key"
                   << "application/xml"
+                  << "application/xhtml+xml"
                   << "application/yaml"
                   << "application/x-zerosize"
                   << "image/svg+xml"