[ICS07] Investigate updating the store in ClientState::initialize() instead of create_client::execute()

[Farhad-Shabani]

Summary

Looking at the spec, we are missing the following check & setting upon initializing a Tendermint client state:

• assert(clientState.trustLevel >= 1/3 && clientState.trustLevel <= 1)
• provableStore.set("clients/{identifier}/clientState", clientState)

[plafer]

We do them, but in different but equivalent places:

assert(clientState.trustLevel >= 1/3 && clientState.trustLevel <= 1)

Here:

ibc-rs/crates/ibc/src/clients/ics07_tendermint/client_state.rs

Lines 102 to 105 in 707d032

	let _ = TendermintTrustThresholdFraction::new(
	trust_level.numerator(),
	trust_level.denominator(),
	)

provableStore.set("clients/{identifier}/clientState", clientState)

Here:

ibc-rs/crates/ibc/src/core/ics02_client/handler/create_client.rs

Line 82 in 707d032

ctx.store_client_state(ClientStatePath::new(&client_id), client_state.clone())?;

2 points:

1. the spec is very often out of date. Looking at ibc-go instead, see that it does not do (1) there either, but does (2).
2. Here, as in ClientState::{update_state, update_state_on_misbehaviour}(), they give the "mutating the store" responsibility to the light client instead of the core handler. I suspect that this comes as a realization that not all clients are updated the same (as we currently assume in ibc-rs). We should investigate whether that makes sense for us as well. Related: Investigate removing ValidationContext argument from light client methods #615