This updates the minimal supported version of CMake to 3.16, which in turn enables us to use more CMake features and have a cleaner build system.
This is the version that provides most new features and also the one we use in our latest docker image for CI.
List of changes:
* New component esp_local_ctrl added
* Example added under examples/protocols/esp_local_ctrl
* Documentation added under protocols/esp_local_ctrl
* Demo client side app esp_local_ctrl.py added under examples/protocols/esp_local_ctrl/scripts
* protocomm_ble : protocomm_ble_config_t given struct name for allowing forward declaration
* esp_prov/transport_softap renamed to transport_http
* transport_http module supports verification of server certificate
* transport_http module performs name resolution before connection
