[DPP] Add new port

[braindigitalis]

What does your PR fix?

Adds support for DPP, a lightweight high performance C++ discord library used in multiple large popular Discord bots

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

linux-x64, linux-x86, windows-x64, windows-x86, windows-arm64, osx-x64
CI baseline not updated

Does your PR follow the maintainer guide?

Yes

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

Yes

[braindigitalis]

can't see logs to find out why this is going wrong... compiled fine for us

[dg0yt]

can't see logs to find out why this is going wrong... compiled fine for us

Via the check details, go to Azure Pipelines, then to the artifacts (" published"), then find the download action on the right side while hovering a "failure logs" item.

[braindigitalis]

ci baseline updated to exclude UWP from tests, set to "fail". this is not a supported platform.

[dg0yt]

ci baseline updated to exclude UWP from tests, set to "fail". this is not a supported platform.

If UWP is not supported, only add "supports": "!uwp" to vcpkg.json. The ci baseline list fail is for ports which should work on a user's machine, but can't in vcpkg CI.

[braindigitalis]

I have changed our versioning to our version numbers as requested.
the value of NO_PREFIX_CORRECTION is required or cmake will not build and deploy the library correctly.

[BillyONeal]

I am very concerned about giving the name "dpp" to this. Repology says that Homebrew already has a "dpp" pointing to https://github.com/atilaneves/dpp which seems to be a different project. However, Google "dpp c++" points to this one conclusively, and that is a tool rather than a library so it wouldn't generally make sense to be a port.

I pushed some nitpick fixes into this; please confirm that you are OK with that @braindigitalis

[braindigitalis]

I am very concerned about giving the name "dpp" to this. Repology says that Homebrew already has a "dpp" pointing to https://github.com/atilaneves/dpp which seems to be a different project. However, Google "dpp c++" points to this one conclusively, and that is a tool rather than a library so it wouldn't generally make sense to be a port.

I pushed some nitpick fixes into this; please confirm that you are OK with that @braindigitalis

these changes all look good to me. we will have to put these changes into the scripts inside our release ci so when we send an update PR these changes will be preserved (e.g. space indentation and https on the URL).

thanks for your time!

[BillyONeal]

Thank you!