TC and compiler should support common keyword parameters in multiple data declarations

[PaulKlint]

One of the recently introduced changes regarding keyword parameters is the handling of common keyword parameters in data declarations: all common keyword parameters apply to all constructors, even if the declaration is spread across several data declarations. For example, m().a should have a value given the following declarations

data L(int a = 1, int b = 2 * a) = l(int c = 2 * b);
data L(int d = -1) = m(); 

The relevant tests can be found in: lang::rascal::tests::functionality::KeywordParameterImportTests.