Creation of a certificate manager wrapper from samples

Description

Move and rename the push_server_lib from the samples to frontend/common_wrapper to use it as a library.

Code version identification

commit 5f8f9004

Current behavior

The push_server_lib is in the samples.

Expected behavior

We want to move the push_server_lib in frontend/common_wrapper to use it as a library.

We want to rename it into "certificate_management".