[microsoft-signalr] Add missing header files

[jimwang118]

One of the fixes for the #32398 issue.
The following error occurs when installing microsoft-signalr[core,messagepack]:x64-linux.

/mnt/vcpkg/buildtrees/microsoft-signalr/src/1.0-alpha4-e34fa42a98/src/signalrclient/binary_message_parser.h:13:62: error: ‘size_t’ has not been declared
/mnt/vcpkg/buildtrees/microsoft-signalr/src/1.0-alpha4-e34fa42a98/src/signalrclient/transport_factory.cpp:26:20: error: ‘runtime_error’ is not a member of ‘std’
Line 39:    26 |         throw std::runtime_error("not implemented");

• Changes comply with the maintainer guide.
• SHA512s are updated for each updated download.
• The "supports" clause reflects platforms that may be fixed by this new version.
• Any fixed CI baseline entries are removed from that file.
• Any patches that are no longer applied are deleted from the port's directory.
• The version database is fixed by rerunning ./vcpkg x-add-version --all and committing the result.
• Only one version is added to each modified port's versions file.

The feature test pass with following triplets:

x64-windows
x64-linux

[BillyONeal]

Can you make sure these are submitted upstream?

[jimwang118]

PR 99 was submitted upstream to fix it.

[BillyONeal]

Thanks for the fixes and submitting upstream!