Closes https://github.com/espressif/esp-idf/issues/2924
1. dhcp_server: suppress send_offer debug output 2. tcpip_adapter: zero-initialize system_event_t structures 3. tcpip_adapter: pass client IP address along with SYSTEM_EVENT_AP_STAIPASSIGNED Closes https://github.com/espressif/esp-idf/issues/2924 Closes https://github.com/espressif/esp-idf/issues/2949