refact(pcf): Adapt PCF config to new structure in common config

src/api-server/api_defs.cpp

src/api-server/pcf-http2-server.cpp

src/common/utils/conversions.cpp

src/common/utils/conversions.hpp

src/oai-cn5g-common-src

src/oai_pcf/main.cpp

src/pcf_app/CMakeLists.txt

src/pcf_app/pcf_app.cpp

src/pcf_app/pcf_client.cpp

src/pcf_app/pcf_config.cpp

src/pcf_app/pcf_config.hpp

src/pcf_app/pcf_config_types.cpp

src/pcf_app/pcf_config_types.hpp

src/pcf_app/pcf_nrf.cpp

src/pcf_app/pcf_sm_policy_control.cpp

src/pcf_app/sm_policy/policy_provisioning_file.cpp