Remove find_package generation on test_package of cmake_lib template

[perseoGI]

Changelog: Fix: Avoid find_package's of transitive dependencies on test_package generated by cmake_lib template. Docs: omit

Close #16450

• [x] Refer to the issue that supports this Pull Request.
• [x] If the issue has missing info, explain the purpose/use case/pain/need that covers this Pull Request.
• [x] I've read the Contributing guide.
• [x] 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.

On test_package/CMakeLists.txt should not appear any find_package of transitive dependencies (dependencies of the currently tested package) Delegate on conan cmake generators to find dependencies.

Also, ordered optional requirements and build_requirement methods on template