修复颠倒英语中括号显示错误的问题

[Glavo]

No description provided.

[Copilot]

Pull Request Overview

This PR optimizes upside down English support by refactoring code to use a utility method and adding additional character mappings for brackets and parentheses.

• Refactored properties loading to use a utility method instead of inline code
• Added character mappings for parentheses, square brackets, and curly braces to the upside down translation table

Reviewed Changes

Copilot reviewed 2 out of 2 changed files in this pull request and generated no comments.

File	Description
UpsideDownTranslate.java	Simplified properties loading by using PropertiesUtils.load() utility method
upside_down.txt	Extended character mapping table with bracket and parentheses translations

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