DHCP Option 114 provides a modern method of indicating a captive
portal redirect to DHCP client. This introduces Option 114 to
the DHCPS component as well as provides examples for usage.
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
