Summary:

This MR introduces the initial skeleton for a centralized extension manager.

Step's Done:

Created extension_manager.c and extension_manager.h under modules/
Defined extension_manager_t struct with a vlc_vector_t for storing loaded extensions
Stubbed build_extension_manager() and vlc_getextensionmanager() functions
Integrated with addon_manager to list Lua extensions of type "extension"
Connected the files to the build system (Makefile/configure)