[Python] adding Vector

[philbucher]

This PR adds the CoSimIO.Vector
this object is a tiny wrapper around std::vector<double> to be used in Python. The goals are:

• Make the data exchange more efficient, having a dedicated object will not require to copy back and forth the data each time (currently pybind does this automatically each time we pass data btw Python & C++)
• The interfaces are now unified, esp for the ImportData we will not need to return a tuple (of CoSimIO.Info & the data (a py::list)) any more but now only the Info

=> the Interface will be updated in a follow up PR

[philbucher]

I managed to get it to work with PYBIND11_MAKE_OPAQUE which is quite cool
=> https://pybind11.readthedocs.io/en/stable/advanced/cast/stl.html#making-opaque-types

basically this disables the automatic copy of the specified types and allows to use the by reference, exactly what we need!

unfortunately this breaks the old Import/ExportMesh tests where I still use them by copy. Hence I need to update those first

TODO for this PR to go in:

• update old tests => [Python] using ModelPart in interface #120
• add more tests with passing the object to the function, modifying it and then checking if the modification is propagated (will probably require some function in C++ for testing) => done in the integration tutorials
• decide on naming: Vector (as it is now) or DoubleVector so that we could easily add an IntVector in the future

[pooyan-dadvand]

I would go for DoubleVector