[Bug 53905] New: widl: support MIDL 3.0 and WinMD output

[WineHQ Bugzilla]

https://bugs.winehq.org/show_bug.cgi?id=53905

Bug ID: 53905
           Summary: widl: support MIDL 3.0 and WinMD output
           Product: Wine
           Version: unspecified
          Hardware: x86-64
                OS: Windows
            Status: UNCONFIRMED
          Severity: normal
          Priority: P2
         Component: tools
          Assignee: [e-mail]
          Reporter: [e-mail]

C++/WinRT (cppwinrt):
https://github.com/microsoft/cppwinrt

It is currently impossible to build the custom components in the cppwinrt test
suite with mingw-w64. For this to work, widl needs to:

- understand MIDL 3.0 syntax,
- generate the ABI header (not required if only using C++/WinRT projection),
- produce .winmd metadata of the component,
- read existing system .winmd metadata (not sure if actually needed).

The MIDL command line for this:

midl.exe /metadata_dir C:\Windows\System32\WinMetadata /winrt /winmd
"D:\a\cppwinrt\cppwinrt_build\x64\Debug\test_component.winmd" /h
"D:\a\cppwinrt\cppwinrt_build\x64\Debug\test_component.h" /ns_prefix /nomidl
test_component.idl

## MIDL 3.0

https://learn.microsoft.com/en-us/uwp/midl-3/intro

What I can tell is missing widl so far:

- MIDL 3.0 uses different basic type names (e.g. Int32, String)
- Attribute types, and using custom attributes

Example file:
https://github.com/microsoft/cppwinrt/blob/5ca626adae21be363399b44d2b6a9ab31...

> widl --winrt -h -H out/test_component.h --ns_prefix test_component.idl
    test_component.idl:5: error: syntax error, unexpected aIDENTIFIER,
expecting ',' or ']'

(widl version 7.7 from mingw-w64)

## WinMD metadata

https://learn.microsoft.com/en-us/uwp/winrt-cref/winmd-files

These are CLR (think .NET and ECMA 335) assemblies used as a replacement for
the old typelib files.