Add support for streaming binary serial read buffers

[glopesdev]

This PR adds support for continuous streaming of fixed size buffers from the low-level SerialRead operator. This makes SerialRead work symmetrically with the SerialReadLine operator. Furthermore we adapted the triggered interface to use the Read methods from serial port for parity with SerialReadLine usage and to allow for interleaving binary and text operators.

Care should be taken to ensure that the binary stream is correctly aligned. Cancellation of blocking operations is supported but the serial port will not be closed until the corresponding subscription to CreateSerialPort is cancelled, or all operators accessing the serial port are cancelled.