IS_MATLAB_ONLINE check if running in MATLAB Online

This function is heuristic check using undocumented environment variables. These variables have worked across several Matlab releases, but there isn't a guarantee that they will always be present or have the same values.

function y = is_matlab_online()

name = "MW_DDUX_APP_NAME";
value = "MATLAB_ONLINE";

y = isunix() && ~ismac() && contains(getenv(name), value);

end