tools: Increase the minimal supported CMake version to 3.16

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.


* Original commit: espressif/esp-idf@facab8c5a7

examples/protocols/asio/asio_chat/CMakeLists.txt

@@ -1,6 +1,6 @@
 # The following lines of boilerplate have to be in your project's CMakeLists
 # in this exact order for cmake to work correctly
-cmake_minimum_required(VERSION 3.5)
+cmake_minimum_required(VERSION 3.16)
 
 # (Not part of the boilerplate)
 # This example uses an extra component for common functions such as Wi-Fi and Ethernet connection.

examples/protocols/asio/async_request/CMakeLists.txt

@@ -1,6 +1,6 @@
 # The following lines of boilerplate have to be in your project's CMakeLists
 # in this exact order for cmake to work correctly
-cmake_minimum_required(VERSION 3.5)
+cmake_minimum_required(VERSION 3.16)
 
 # (Not part of the boilerplate)
 # This example uses an extra component for common functions such as Wi-Fi and Ethernet connection.

examples/protocols/asio/socks4/CMakeLists.txt

@@ -1,6 +1,6 @@
 # The following lines of boilerplate have to be in your project's CMakeLists
 # in this exact order for cmake to work correctly
-cmake_minimum_required(VERSION 3.5)
+cmake_minimum_required(VERSION 3.16)
 
 # (Not part of the boilerplate)
 # This example uses an extra component for common functions such as Wi-Fi and Ethernet connection.

examples/protocols/asio/ssl_client_server/CMakeLists.txt

@@ -1,6 +1,6 @@
 # The following lines of boilerplate have to be in your project's CMakeLists
 # in this exact order for cmake to work correctly
-cmake_minimum_required(VERSION 3.5)
+cmake_minimum_required(VERSION 3.16)
 
 # (Not part of the boilerplate)
 # This example uses an extra component for common functions such as Wi-Fi and Ethernet connection.

examples/protocols/asio/tcp_echo_server/CMakeLists.txt

@@ -1,6 +1,6 @@
 # The following lines of boilerplate have to be in your project's CMakeLists
 # in this exact order for cmake to work correctly
-cmake_minimum_required(VERSION 3.5)
+cmake_minimum_required(VERSION 3.16)
 
 # (Not part of the boilerplate)
 # This example uses an extra component for common functions such as Wi-Fi and Ethernet connection.

examples/protocols/asio/udp_echo_server/CMakeLists.txt

@@ -1,6 +1,6 @@
 # The following lines of boilerplate have to be in your project's CMakeLists
 # in this exact order for cmake to work correctly
-cmake_minimum_required(VERSION 3.5)
+cmake_minimum_required(VERSION 3.16)
 
 # (Not part of the boilerplate)
 # This example uses an extra component for common functions such as Wi-Fi and Ethernet connection.