Debugger relies on case-insensitive paths

This odd behavior was first noticed in a test:

https://github.com/PowerShell/PowerShellEditorServices/blob/bfe334df7e4bdd4b92c5c0319655e40444e185ff/test/PowerShellEditorServices.Test/Debugging/DebugServiceTests.cs#L140-L141

It turns out that the URIs and paths we're receiving "over the wire" (in the raw LSP requests themselves) are mostly cased correctly, with the exception of driver letters being lower case. Because of this, when https://github.com/PowerShell/PowerShell/issues/20057 was temporarily fixed by making PowerShell's debugger's _pendingBreakpoints collection case-sensitive, it broke the extension's debugger https://github.com/PowerShell/vscode-powershell/issues/4668.

We need to figure out why those drive letters are coming over lower-case, as the rest of the Windows ecosystem doesn't expect drive letters to be lowercase. Worst case scenario is that we fix the casing as we handle the request, but I'd like to see where the issue originates (thinking perhaps in the LSP client library...) and try to fix it there. Though technically c:/ is valid, and it's mostly PowerShell that's caring about it not being C:/.

从 test/PowerShellEditorServices.Test/Debugging/DebugServiceTests.cs 的第 140-141 行附近开始，重现大小写行为。跟踪原始 LSP 请求和带盘符的路径是如何处理的，包括所引用的 LSP 客户端库。确定盘符变为小写的来源，并通过回归测试或适当的修复覆盖调试器行为，即视为完成。