[imguizmo] new port

[JonathanHiggs]

Adding a port for the ImGuizmo library to go along with ImGui and ImPlot

Source library uses a make build so this port uses the same method of ImPlot to define a CMakeLists.txt in the port and copy it over during install to correctly build the project

Source library is not versioned, I have an open issue about whether there they will use releases. Currently I am using a yyyy-mm-dd as the version string

• What does your PR fix?

  Adds a port for ImGuizmo

• Which triplets are supported/not supported? Have you updated the [CI baseline]

  Tested x86-windows, x64-windows, x64-linux sucessfully, unable to test others

• Does your PR follow the maintainer guide?

  As far as I know. Port is very similar to pre-existing ImPlot port, and the example code in source repo is excluded by the custom CMakeLists.txt included in the port directory

• If you have added/updated a port: Have you run ./vcpkg x-add-version --all and committed the result?

  Yes

If you are still working on the PR, open it as a Draft: https://github.blog/2019-02-14-introducing-draft-pull-requests/

[ghost]

All CLA requirements met.

[JonLiu1993]

@JonathanHiggs ,Please take a look:
https://dev.azure.com/vcpkg/public/_build/results?buildId=56231&view=artifacts&pathAsName=false&type=publishedArtifacts

[JonLiu1993]

@JonathanHiggs ,Could you please take a look?
https://dev.azure.com/vcpkg/public/_build/results?buildId=56292&view=artifacts&pathAsName=false&type=publishedArtifacts

[JonathanHiggs]

Does osx run without std11 even?

[PhoebeHui]

@JonathanHiggs, you need 'add_compile_options(-std=c++11)' in your CMakeLists.txt for osx if it needed.

[JonathanHiggs]

Is it add_compile_options() or target_compile_options() I need to set the cxx std? Will the both work cross-platform?

[PhoebeHui]

@JonathanHiggs, please use target_compile_options().

[vicroms]

Thanks for the PR!