[rcore] GLFW does not use Raylib-provided RL_*ALLOC macros for memory allocations

[sleeptightAnsiC]

Raylib has a support for providing custom heap memory allocators by defining RL_MALLOC / RL_CALLOC / RL_REALLOC / RL_FREE macros. GLFW supports this too, but with function pointers passed into glfwInitAllocator() call. Currently, raylib does not use glfwInitAllocator anywhere, and so GLFW always uses default LibC allocators, which is undesired.

I noticed that there is some code in src/platforms/rcore_desktop_glfw.c that was meant to support this, but it is currently commented-out with a TODO note:

raylib/src/platforms/rcore_desktop_glfw.c

Lines 1290 to 1305 in 11090ab

	// Initialize platform: graphics, inputs and more
	int InitPlatform(void)
	{
	glfwSetErrorCallback(ErrorCallback);
	/*
	// TODO: Setup GLFW custom allocators to match raylib ones
	const GLFWallocator allocator = {
	.allocate = MemAlloc,
	.deallocate = MemFree,
	.reallocate = MemRealloc,
	.user = NULL
	};
	glfwInitAllocator(&allocator);
	*/

Related to #4751

[I'll make a PR for this in a moment]