[signal] Fix the macros declaring signals

DECLARE_SIGNAL_IN, CONSTRUCT_SIGNAL_IN, DECLARE_SIGNAL_OUT and CONSTRUCT_SIGNAL_OUT

The macros were duplicated in various SoT packages.
Unify them by:
* Adding prefix m_ and suffix SIN for input signals
declared as fields of entity classes.
* Adding prefix m_ and suffix SOUT for output signals
declared as fields of entity classes.