[backward-cpp] Remove cpp_info.names for cmake generator

[danimtb]

Specify library name and version: backward-cpp/all

closes #787
Related to conan-io/hooks#142

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• I've followed the PEP8 style guides for Python code in the recipes.
• I've used the latest Conan client version.
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  conan-center hook activated.

[jgsogo]

What is the name of the CMake target created by the cmake generator? As it contains a - in the name... I'd like to know which one is the actual name there.

Thanks!

[conan-center-bot]

All green in build 1 (2e9cd6de1bdd7c563a8b0643aa1ca7805776633b)! 😊

• backward-cpp/1.4: Generated 100 packages. All logs here

[Morwenn]

It will be CONAN_PKG::backward-cpp, which works despite the -.