Newton backend for state estimator synthesis

[KomaGR]

Create a new irPass for Newton as a backend for state estimator synthesis.

[KomaGR]

Need the distribution notation (#462) to provide uncertainty input ability in the .nt specification of a given system.

[btsouts]

Extra parameters symbols that were not part of the state were parameters of the filterPredict function, but had to be manually declared in the output C source code of the state estimation backend. With the b0da408 commit, the extra parameter symbols are automatically declared as C source code variables but are NOT initialized. Correct initialization should still be performed manually.