Add newtypes for ids in ibc-union-spec

[benluelo]

Currently these are just raw type aliases:

union/lib/ibc-union-spec/src/lib.rs

Lines 484 to 486 in 7bac27e

	type ClientId = u32;
	type ConnectionId = u32;
	type ChannelId = u32;

These should instead be proper newtypes wrapping a NonZeroU32 (since 0 is specified as the "nonexistentent" sentinel value for all ids). Anywhere where an id may be missing should be wrapped in an Option, similar to how it is done throughout the types used in ibc-classic-spec (example).

One issue that we'll hit (and the main reason why this isn't done yet) is that the state types in union-ibc require the keys and values to implement certain cosmwasm-specific traits in order to be used in the storage maps/items:

union/cosmwasm/union-ibc/core/src/state.rs

Lines 7 to 34 in 7bac27e

	pub const QUERY_STORE: Item<Binary> = Item::new("query_store");
	pub const CHANNEL_OWNER: Map<u32, Addr> = Map::new("channel_owner");
	pub const CHANNELS: Map<u32, Channel> = Map::new("channels");
	pub const CONTRACT_CHANNELS: Map<Addr, BTreeSet<u32>> = Map::new("contract_channels");
	pub const CONNECTIONS: Map<u32, Connection> = Map::new("connections");
	pub const CLIENT_STATES: Map<u32, Binary> = Map::new("client_states");
	pub const CLIENT_CONSENSUS_STATES: Map<(u32, u64), Binary> = Map::new("client_consensus_states");
	// From client type to contract implementation
	pub const CLIENT_REGISTRY: Map<&str, Addr> = Map::new("client_registry");
	// From client id to client type
	pub const CLIENT_TYPES: Map<u32, String> = Map::new("client_types");
	// From client id to contract implementation
	pub const CLIENT_IMPLS: Map<u32, Addr> = Map::new("client_impls");
	pub const NEXT_CLIENT_ID: Item<u32> = Item::new("next_client_id");
	pub const NEXT_CONNECTION_ID: Item<u32> = Item::new("next_connection_id");
	pub const NEXT_CHANNEL_ID: Item<u32> = Item::new("next_channel_id");

Rather than bringing in the cosmwasm traits into the ibc-union-spec crate (which we definitely don't want to do), we should instead keep the storage id key/values as raw u32s, and expose helpers that wrap in the relevant types. We already do this in some places:

union/cosmwasm/union-ibc/core/src/contract.rs

Lines 1558 to 1560 in 7bac27e

	fn next_channel_id(deps: DepsMut) -> Result<u32, ContractError> {
	increment(deps, NEXT_CHANNEL_ID)
	}

so hopefully this change won't be too drastic or invasive.

NOTE: This issue is labelled with all of A-cosmwasm, A-lightclients, and A-voyager since these spec crates touch a large portion of our codebase. That being said, the changes themselves are quite simple, just also quite pervasive. A small price to pay for type safety and reusable code 😁

[benluelo]

This is soft blocked on #3919