Refactor Admin cw-controller to better represent actual functionality

[ueco-jb]

Follow-up of https://github.com/confio/tgrade-contracts/pull/124#discussion_r709188534

When I read admin's tests I completely missed point of tested operations without reading implementation.
https://github.com/CosmWasm/cw-plus/blob/main/packages/controllers/src/admin.rs#L102

let control = Admin::new("foo");
let admin = Some(Addr::unchecked("admin"));
control.set(deps.as_mut(), admin.clone()).unwrap();
let got = control.get(deps.as_ref()).unwrap();
assert_eq!(admin, got);

Later this might be the case as well in production code.

I see some room for improvements in renaming those methods to better illustrace fact that operations are performed on addreses.

[hashedone]

Honestly I don't see it. In the example you quoted the problem is the name of variable - why is this control instead of admin? Let try it that way:

let admin = Admin::new("foo");
admin.set(deps.as_mut(), Some(Addr::unchecked("admin")).unwrap();
let admin_addr = admin.get(deps.as_ref()).unwrap();
assert_eq!(Some(Addr::unchecked("admin")), admin_addr);

The most strrange is execute_update_admin, but I don't see better name for it. However if you have idea for better names - feel free to propose them :)

[ueco-jb]

However if you have idea for better names - feel free to propose them :)

I found it confusing at start. For me there's no clear connection that Admin is an Option<Addr>, which found it's epitome in test in which Admin was named control on top of that.

However if you assossiate Admin with an address, then methods like admin.get or set starts making sense...

I was considering something as simple as renaming methods to set_addr, but it doesn't make better sense since Addr is an optional so it's actually setting an admin, given that admin is this Item<'a, Option<Addr>>...

I will close this issue, because in order to satisfy my accusations I'd have to rewrite whole controller, which doesn't make sense as well since it's working well and everyone (eventually) will understand it.