x/wasm hooks

For a couple of months I've been thinking about a cosmwasm system where there can be namespaces: ability to upload codes to a namespace where they can interact each other but also open permissions to other namespaces you can think of like linux namespaces and a firewall.

First I thought just playing around with a fork but then I think that this could also be achieved if another module had access to hooks like
```
BeforeInstantiate()
BeforeExecute()
BeforeStore()
BeforeMigrate()
```
then an`x/namespace` module can just subscribe to hooks and apply whatever logic.

This is just an idea but not sure if others would find this interesting our useful