C++: Moved all C++ examples to own folder

* moved C++ examples to a new cxx folder in
  examples
* added experimental C++ component
* added ESPException class to the C++ experimental
  component
* added test cases for ESPException and
  corresponding test macros

examples/cxx/rtti/example_test.py

@@ -0,0 +1,25 @@
+from __future__ import print_function
+
+import ttfw_idf
+
+
+@ttfw_idf.idf_example_test(env_tag='Example_WIFI')
+def test_cpp_rtti_example(env, extra_data):
+    dut = env.get_dut('cpp_rtti', 'examples/system/cpp_rtti', dut_class=ttfw_idf.ESP32DUT)
+    dut.start_app()
+
+    dut.expect('Type name of std::cout is: std::ostream')
+    dut.expect('Type name of std::cin is: std::istream')
+    dut.expect('Type of app_main is: void ()')
+    dut.expect('Type name of a lambda function is: app_main::{lambda(int, int)#1}')
+
+    dut.expect('dynamic_cast<DerivedA*>(obj)=0')
+    dut.expect('dynamic_cast<DerivedB*>(obj)=0x')
+    dut.expect('dynamic_cast<DerivedB*>(obj)=0')
+    dut.expect('dynamic_cast<DerivedA*>(obj)=0x')
+
+    dut.expect('Example finished.')
+
+
+if __name__ == '__main__':
+    test_cpp_rtti_example()