Fork from autowp/arduino-canhacker.

Selection of CAN controller is performed by define USE_ESP32_INTERNAL_CAN

The Main features are preserved, but there are some issues:

• no interrupt mode, only polling
• no loopback mode
• no listen-only mode
• bad CAN bitrate calculation (125kbps is 250kbps, 250kbps is 500kbps and so on)
• to keep original code, the ESP32SJA1000Class::filterMask() should be separated to two functions for setting filter and mask. And there is still issues with it. Anyway, this code needs to rework.