Add sharedlibpp C++ library

[traversaro]

sharedlibpp is simple C++ library used to permit to easily implement a cross-platform plug-in system (i.e. enabling to load classes with arbitrary interfaces from dll, so, dylib, depending on the operating system).

The proposed recipe adds a single package:

• libsharedlibpp: This is the package that is meant to be used if the package is consumed as a C/C++ library, and linked to a downstream project. To do so, the package contains a run_exports section. This package name contains the lib prefix as requested in Add recipe for libmatio-cpp #19764 (review) for C/C++ libraries.

The feedstock is named sharedlibpp to match the repo name and to permit to easily add new outputs if necessary in the future.

Checklist

• Title of this PR is meaningful: e.g. "Adding my_nifty_package", not "updated meta.yaml".
• License file is packaged (see here for an example).
• Source is from official source.
• Package does not vendor other packages. (If a package uses the source of another package, they should be separate packages or the licenses of all packages need to be packaged).
• If static libraries are linked in, the license of the static library is packaged.
• Package does not ship static libraries. If static libraries are needed, follow CFEP-18.
• Build number is 0.
• A tarball (url) rather than a repo (e.g. git_url) is used in your recipe (see here for more details).
• GitHub users listed in the maintainer section have posted a comment confirming they are willing to be listed there.
• When in trouble, please check our knowledge base documentation before pinging a team.

[github-actions]

Hi! This is the staged-recipes linter and your PR looks excellent! 🚀

[conda-forge-admin]

Hi! This is the friendly automated conda-forge-linting service.

I just wanted to let you know that I linted all conda-recipes in your PR (recipes/sharedlibpp/meta.yaml) and found it was in an excellent condition.

[traversaro]

@conda-forge/staged-recipes @conda-forge/help-c-cpp the PR is ready for review, thanks!

[github-actions]

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