Add tutorial on memory management

See Issue https://github.com/Project-MONAI/MONAI/issues/6626 relating to memory management and interaction with the garbage collector. One solution that we've tried before and had success with was to use the GarbageCollector handler to clean unused references at certain times. This isn't ideal and not particularly Pythonic but without changes to the garbage collector to consider GPU memory there may be little choice. Certain design decisions and good practices can reduce the issue so a tutorial on the problem and how to deal with OOM issues would be really helpful.

Comienza leyendo el issue enlazado #6626 y revisando el enfoque del handler de GarbageCollector descrito aquí. Crea un tutorial que cubra el problema de la gestión de memoria, las prácticas de diseño que reducen los problemas de falta de memoria y cómo el handler puede ayudar a limpiar las referencias no utilizadas. Se considerará terminado cuando el tutorial explique claramente el problema y las formas prácticas de abordarlo.