Allow wsl$ in file URIs; generally allow all URI schemes

[zadjii-msft]

Does two things related to URLs emitted via OSC8.

• Allows wsl$ and wsl.localhost as the hostname in file:// URIs
• Generally allows all URIs that parse as a URI.

The relevant security comments: #7526 (comment)

this doesn't let a would-be attacker specify command-line arguments (ala "cmd.exe /s /c do_a_bad_thing") (using somebody else's reputation to cause mayhem)

ShellExecute de-elevates because it bounces a launch request off the shell

"Works predictably for 15% of applications" (h/t to PhMajerus' AXSH, and other on-Windows requestors) is better in so many ways than "Works for 0% of applications", in my estimation. Incremental progress 😄 while we work on features that'll make it even more broadly applicable.

Closes #10188
Closes #7562

discuss

[DHowett]

I'm cool with this.

[carlos-zamora]

@msftbot merge this in 10 minutes

EDIT: or ignore me, that works too, I guess

[Araxeus]

This is great, so many possibilities !

I'm just a random guy wondering if the first if is necessary in this function

terminal/src/cascadia/TerminalApp/TerminalPage.cpp

Lines 2463 to 2466 in be62c22

	if (parsedUri.SchemeName() == L"http" || parsedUri.SchemeName() == L"https")
	{
	return true;
	}

the function would return true anyways right?

[heaths]

@Araxeus necessary, no, but IMO it's better to maintain. You're still explicitly allowing HTTP/S but that fallback may change in the future. Will future maintainers remember to explicitly handle HTTP/S again? A lot would be broken if not. Also allows more understandable comments, IMO, and is neither a hot path nor all that slow anyway so a refactor doesn't seem worth the potential maintenance issues.