Add pokemon lock in pokemon storage to avoid accidental release

[Mg3]

As the title said, adding pokemon lock in pokemon storage can help avoid accidental release. We need a lock feature to lock those pokemons that we certainly are not going to release, when we really want to release locked ones, we may unlock first then release it.

[Sin]

Not really a must, but sounds helpful, so +1. 

Usually I let the Poke I don't want to accidentally delete to hold a Berry, so maybe changing the coding so that you can't release a Poke holding an item is also feasible and less work for the dev to do.

Edited May 16, 2022 by Sin

[Sefanne]

Was just about to suggest this. Bump