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.
This commit updates the visibility of various header files and cleans up
some unnecessary inclusions. Also, this commit removes certain header
include paths which were maintained for backward compatibility.
Feature note: Sets up a simple DNS server that answers all questions with the ESP softAP's IP as well as a HTTP server which redirects all requests to a captive portal welcoming page.
Triggers captive portal detection (log-in screen popup) for iOS, Android and Windows.
Includes example test for testing DNS redirect and HTTP redirect.
Closes https://github.com/espressif/esp-idf/issues/7099
Closes https://github.com/espressif/esp-idf/issues/4075
