Use NativeStorage trait bound for AccessoryState related things

[citizen-stig]

There are 2 ways to define Storage capabilities in Zk and Native mode:

1. native flag
2. NativeStorage trait bound

Currently both approaches are used, but I believe that second provides clearer type control, example can be seen in
#978

This issue suggest removing fn get_accessory(&self, key: &StorageKey) -> Option<StorageValue> from Storage trait and move it to NativeStorage trait.

This change will heavily affect sov-modules-api, as many things there probably needs to be feature gated behind native flag.
Upside is that binary size for Zkvm should be smaller.