feat: add default color mode configuration for print preview

sync with dtkwidget/develop/eagle
309f339dfa9f45921efa2b32e9a5cb7b0cd686c5
Added two new configuration options for print preview color mode
settings:
1. defaultColorMode - public setting with default value "color" for
default color mode configuration
2. colorMode - private setting for current color mode configuration with
empty default value

These configurations support v20 migration requirements for print
preview functionality, providing both a default color mode setting and
a current color mode state management. The defaultColorMode is publicly
accessible while colorMode is kept private for internal state tracking.

Log: Added default color mode configuration option for print preview

Influence:
1. Test print preview functionality with different color mode settings
2. Verify default color mode is properly applied when no specific mode
is set
3. Check configuration persistence across application sessions
4. Validate that public defaultColorMode setting can be modified by
users
5. Ensure private colorMode setting is not directly accessible to end
users

feat: 为打印预览添加默认色彩配置

新增两个打印预览色彩模式配置选项：
1. defaultColorMode - 公开设置，默认值为"color"，用于配置默认色彩模式
2. colorMode - 私有设置，用于当前色彩模式配置，默认值为空

这些配置支持v20迁移的打印预览功能需求，提供默认色彩模式设置和当前色彩模
式状态管理。defaultColorMode为公开可访问，而colorMode保持私有用于内部状
态跟踪。

Log: 新增打印预览默认色彩配置选项

Influence:
1. 测试不同色彩模式设置下的打印预览功能
2. 验证未设置特定模式时默认色彩模式是否正确应用
3. 检查配置在应用程序会话间的持久性
4. 验证公开的defaultColorMode设置是否可被用户修改
5. 确保私有colorMode设置对最终用户不可直接访问

Author: 18202781743

configs/org.deepin.dtk.preference.json

@@ -106,6 +106,26 @@
             "description[zh_CN]": "配置是否开启紧凑模式, 0为禁用, 1为启用",
             "permissions": "readwrite",
             "visibility": "public"
+        },
+        "defaultColorMode": {
+            "value": "color",
+            "serial": 0,
+            "flags": [],
+            "name": "Default Color Mode config",
+            "name[zh_CN]": "默认色彩配置",
+            "description": "Default Configure the color mode",
+            "permissions": "readwrite",
+            "visibility": "public"
+        },
+        "colorMode": {
+            "value": "",
+            "serial": 0,
+            "flags": [],
+            "name": "Color Mode config",
+            "name[zh_CN]": "色彩配置",
+            "description": "Configure the color mode",
+            "permissions": "readwrite",
+            "visibility": "private"
         }
     }
 }