Fix: Add missing LIBRARY and FOUND vars in cmake find_package() generator

[igxactly]

Changelog: Fix: Add missing vars in cmake find_package() generator: <PACKAGE>_LIBRARY_DIRS, <PACKAGE>_<COMPONENT>_LIBRARY, <PACKAGE>_<COMPONENT>_FOUND
Docs: missing

Fix #9444

• I've read the Contributing guide.
• I've followed the PEP8 style guides for Python code.
• I've opened another PR in the Conan docs repo to the develop branch, documenting this one.
  • I could not find where to put changelog. It seems like it is for maintainers.

[CLAassistant]

All committers have signed the CLA.

[memsharded]

These generators are considered "legacy", and this kind of change should go first to CMakeDeps, and only in some cases we would consider backporting them to other generators.

[memsharded]

Hi @igxactly

In case you would consider submitting these changes for CMakeDeps, please note that there are ongoing changes to add explicit support for "find" modules instead of Config files. At the moment CMakeDeps only implement CMake xxx-config.cmake files, but support for find modules is being drafted in #9455. Thanks!