Update documentation for the ECSS definitions

Group Services and ECSS Definitions into a doxygen page

Suggested by @xlxs4

Other changes:
Tweaked addNewParameter() in order for the IDs to be arbitrary (insertion
of already existing ID test incoming) according to suggestion by @kongr45gpen

Cause was an off-by-1 error in construction of the Parameter objects.
Minor changes to documentation

Need to fix linker errors. Also updated documentation.

in order to make construction and adding more natural

Update the tests and documentation to reflect the fact that the service functions are now properly returning the ST[1, 4] failed start of execution notification when needed

Prepare for replacement of if statements checking message type with assertions and proper notification messages provided by ErrorHandler