Add singleton implementation to `serial_channel`
the `serial_channel` now use the `abstract_singleton` implementation.
It is only possible to get an `serial_channel` instance through `singleton_mgr`.

Conflicts:
	se2p_2_3/src/lib/serial_bus/serial_channel.cpp
	se2p_2_3/src/lib/serial_bus/serial_channel.hpp
Some work on `serial_channel`

Conflicts:
	se2p_2_3/src/lib/serial_bus/serial_interface.hpp
Add functionality to `serial_channel`
Fix compilation after cherry picking