feat: add plain text copy functionality for messages and topics. 添加了复制纯文本的功能（去除Markdown格式符号） (#5965)

* feat: add plain text copy functionality for messages and topics.

* refactor: move minapp settings to minapp page

* fix: add success message after copying topic and message as text

* fix: refactor test imports and add mocks for translation and window.message

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Co-authored-by: Guscccc <Augustus.Li@outlook.com>
Co-authored-by: kangfenmao <kangfenmao@qq.com>
Co-authored-by: 自由的世界人 <3196812536@qq.com>

package.json

@@ -94,6 +94,7 @@
     "officeparser": "^4.1.1",
     "os-proxy-config": "^1.1.2",
     "proxy-agent": "^6.5.0",
+    "remove-markdown": "^0.6.2",
     "selection-hook": "^0.9.23",
     "tar": "^7.4.3",
     "turndown": "^7.2.0",