Add modifier argument to getModelInstance

[perost]

• Add an argument to getModelInstance that makes it possible to supply a modifier to use when instantiating the model.
• Fix Static.elabCodeType to make it possible to use modifiers and expressions as default arguments in ModelicaBuiltin.

Fixes #10349

[perost]

@adeas31: This doesn't work with OMEdit yet because I'm using the same $Code interface as e.g. setElementModifierValue, which seems to cause API functions to not be added to the OMCInterface.

I'm not sure if we can make that work, I notice that setElementModifierValue uses sendExpression in OMEdit which doesn't return a value. So maybe we shouldn't be using $Code and just have the modifier as a string argument instead?

[adeas31]

Yeah we can use string argument.

[perost]

Yeah we can use string argument.

Ok, I've changed it to be a string now instead. The format is the same as with $Code, just as a string instead. E.g. getModelInstance(M, "(x = 1, redeclare Real y = 4)").

Also be aware that I added the modifier as the second argument, so if you have any script with e.g. getModelInstance(M, true) it will fail since prettyPrint is now the third argument instead (to follow the convention of having flag arguments last).