[Grbl_Esp32 PR#506] Clang format

– Added .clang-format file and applied it throughout the code base. Did not change any of the logic; this is already a big change!
– Disabled clang-format in grbl.h. This is way too sensitive for re-ordering.
– Fixed include order where appropriate as a result of the re-ordering in clang-format. Added includes in cpp files where needed.
– Removed the ifdef for websocket in the header file. Since the pointer is forward declarated, it makes no difference on the runtime.
– Added platformio version of Visual Studio solution for compilation.
– Added a few rules to the gitignore; we don’t want build files in the repo.