Refactor to use octaveMex and dynamic DLL loading

Refactored code to replace matlabMex with octaveMex function names.
Updated Initialize function to dynamically load libmexlibczi.dll
from the same directory as the MEX file. Added IsDynamicLibraryLoaded
function to check if the library and its functions are loaded
successfully. Updated mexFunction to initialize the library only
once and check if the dynamic library is loaded before proceeding.
Removed old and commented-out code. Updated g_appExtensionFunctions
struct to use new octaveMex function names. Added error handling
to ensure appropriate error messages are displayed if the library
fails to load.