* spi cxx unit test (CATCH-based, on host) * added portmacro.h to driver mocking * added simple testing app to write/read SPI, using an MPU9250
Apply the pre-commit hook whitespace fixes to all files in the repo. (Line endings, blank lines at end of file, trailing whitespace)
* 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