Investigate using new C++ MATLAB Engine API

[szhorvat]

We use the old C MATLAB Engine API. Our experience was that it is buggy, slow and has many limitations.

We should investigate using the new C++ API. It seems to have the ability to connect to a shared session. This might enable connecting to an already running MATLAB instance with MATLink even on Mac/Linux. Currently, MATLink can only do this (unofficially) on Windows. This ability would be enormously useful.

We also need to find out which MATLAB version introduced this API. I suspect it is something fairly recent.

[szhorvat]

(It may have been introduced in R2017b, see individual function doc pages: https://uk.mathworks.com/help/matlab/apiref/matlab.engine.connectmatlab.html)