Implement UriCreationOptions

[MihaZupan]

Fixes #52628
Fixes #58057

Implements a minimal subset of #59099:
The Uri constructor overloads and the DangerousDisablePathAndQueryCanonicalization property of UriCreationOptions.

Not yet implemented:

public struct UriCreationOptions
{
    public UriKind UriKind { readonly get; set; }
    public bool AllowImplicitFilePaths { readonly get; set; }
}

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Issue Details

---

Implements a minimal subset of #59099:
The Uri constructor overloads and the DangerousDisablePathAndQueryCanonicalization property of UriCreationOptions.

Not yet implemented:

public struct UriCreationOptions
{
    public UriKind UriKind { readonly get; set; }
    public bool AllowImplicitFilePaths { readonly get; set; }
}

Author:	MihaZupan
Assignees:	-
Labels:	area-System.Net
Milestone:	7.0.0

[Tratcher]

Offline discussion: I'm concerned that there's no way for the consumer to know if DisablePathAndQueryCanonicalization is set and avoid this exception. This method can also throw IOE for relative Uris, but there you can check IsAbsoluteUri first.

[MihaZupan]

This method can also throw IOE for relative Uris, but there you can check IsAbsoluteUri first.

In the current version this is unreachable for relative Uris (since UriKind hasn't been exposed yet), but I will keep it in mind when adding the rest of the API. It's not critical as it would always throw anyway, but the change wasn't intentional.

[geoffkizer]

I think we should consider adding a way to expose this, something like IsPathAndQueryCanonicalizationDisabled.

[karelz]

Just to be super-clear: We can track that for 7.0, we do not consider it blocking attempt for 6.0 backport.
@geoffkizer please let us know if you disagree.

[MihaZupan]

Test failure unrelated: #58356

[RussKie]

Could you please explain what readonly get does, and link me to associated docs? Thank you

[stephentoub]

https://docs.microsoft.com/en-us/dotnet/csharp/language-reference/builtin-types/struct#readonly-instance-members

[karelz]

/backport to release/6.0-rc2

[github-actions]

Started backporting to release/6.0-rc2: https://github.com/dotnet/runtime/actions/runs/1246572044