[cinatra] Fixes microsoft/vcpkg#38712 added async-simple dependency and installed the iguana

[EmployeeNo427]

Fixes microsoft/vcpkg#38712

This PR fixes the Cinatra port by adding the proper async-simple dependency and installing the iguana so that all includes resolve correctly.

If this PR updates an existing port, please uncomment and fill out this checklist:

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

END OF PORT UPDATE CHECKLIST

[Cheney-W]

1. Please modify the ports\cinatra\vcpkg.json as below:

  "name": "cinatra",
  "version": "0.9.5",
  "port-version": 1,

2. Please use vcpkg_from_github() download the source of qicosmos/iguana. Iguana exists in the Cinatra repository as a submodule (or link), so it needs to be downloaded separately.

[vicroms]

Marking as draft until review comments have been addressed, please mark as ready for review when you're done.

[BillyONeal]

• [x] Changes comply with the maintainer guide.
• [x] The name of the port matches an existing name for this component on https://repology.org/ if possible, and/or is strongly associated with that component on search engines.
• [ ] Optional dependencies are resolved in exactly one way. For example, if the component is built with CMake, all find_package calls are REQUIRED, are satisfied by vcpkg.json's declared dependencies, or disabled with CMAKE_DISABLE_FIND_PACKAGE_Xxx.

https://github.com/qicosmos/iguana/blob/9c9ddabfa2dc6db9b548052a473b6c2808009c43/CMakeLists.txt#L121 Missing dependency on protobuf?

• [x] The versioning scheme in vcpkg.json matches what upstream says.
• [x] The license declaration in vcpkg.json matches what upstream says.
• [x] The installed as the "copyright" file matches what upstream says.
• [x] The source code of the component installed comes from an authoritative source.
• [x] The generated "usage text" is accurate. See adding-usage for context.
• [x] The version database is fixed by rerunning ./vcpkg x-add-version --all and committing the result.
• [x] Only one version is in the new port's versions file.
• [x] Only one version is added to each modified port's versions file.