Don't rely on Uri.ToString() in Serializer

[TylerLeonhardt]

In the AbsoluteUriConverter class, we use Uri.ToString().

csharp-language-server-protocol/src/Protocol/Serialization/Converters/AbsoluteUriConverter.cs

Line 54 in 2b06e03

writer.WriteValue(uriValue.ToString());

Unfortunately, the Uri.ToString() has bizarre behavior with Uris with escaped non-ASCII characters.

> new Uri("/Users/tyleonha/Code/PowerShell/Misc/测试.ps1").ToString()
file:///Users/tyleonha/Code/PowerShell/Misc/%E6%B5%8B%E8%AF%95.ps1/Users/tyleonha/Code/PowerShell/Misc/测试.ps1

Notice the path is written twice?

This only seems to happen on non-Windows as adding a drive letter fixes it... but then it url decodes the characters:

> new Uri("file:///C:/Users/tyleonha/Code/PowerShell/Misc/%E6%B5%8B%E8%AF%95.ps1").ToString()
file:///C:/Users/tyleonha/Code/PowerShell/Misc/测试.ps1

But then again... since VS Code expects the colon to be escaped in the drive letter... we're still left in a bad state:

new Uri("file:///C%3A/Users/tyleonha/Code/PowerShell/Misc/%E6%B5%8B%E8%AF%95.ps1").ToString()
file://%2FC%3A%2FUsers%2Ftyleonha%2FCode%2FPowerShell%2FMisc%2F测试.ps1/C%3A/Users/tyleonha/Code/PowerShell/Misc/测试.ps1

[TylerLeonhardt]

So I think something like this... but in C# should do the trick:

# Test cases
$uri = [uri]::new("C:\Users\tyleonha\Code\PowerShell\Misc\foo.ps1")
# or
$uri = [uri]::new("/Users/tyleonha/Code/PowerShell/Misc/测试.ps1")
# or
$uri = [uri]::new("file:///C%3A/Users/tyleonha/Code/PowerShell/Misc/%E6%B5%8B%E8%AF%95.ps1")
# or
$uri = [uri]::new("file:///C%3A/Users/tyleonha/Code/PowerShell/Misc/foo.ps1")
# or
$uri = [uri]::new("file:///C:/Users/tyleonha/Code/PowerShell/Misc/%E6%B5%8B%E8%AF%95.ps1")

$uri.Scheme + "://" + ($uri.Segments -join '')

These all work as expected - the characters are escaped if they should be.